Former Russian tycoon Mikhail Khodorkovsky speaks about his "Open Russia" movement at the Council on Foreign Relations in New York October 6, 2014. REUTERS/Brendan McDermid (UNITED STATES - Tags: BUSINESS POLITICS HEADSHOT) 

Former Russian tycoon Mikhail Khodorkovsky speaks about his "Open Russia" movement at the Council on Foreign Relations in New York October 6, 2014. REUTERS/Brendan McDermid (UNITED STATES - Tags: BUSINESS POLITICS) 

Former Russian tycoon Mikhail Khodorkovsky speaks about his "Open Russia" movement at the Council on Foreign Relations in New York October 6, 2014. REUTERS/Brendan McDermid (UNITED STATES - Tags: POLITICS BUSINESS) 

Former Russian tycoon Mikhail Khodorkovsky speaks about his "Open Russia" movement at the Council on Foreign Relations in New York October 6, 2014. REUTERS/Brendan McDermid (UNITED STATES - Tags: BUSINESS POLITICS) 

Former Russian tycoon Mikhail Khodorkovsky speaks about his "Open Russia" movement at the Council on Foreign Relations in New York October 6, 2014. REUTERS/Brendan McDermid (UNITED STATES - Tags: POLITICS BUSINESS HEADSHOT) 

Former Russian tycoon Mikhail Khodorkovsky speaks about his "Open Russia" movement at the Council on Foreign Relations in New York October 6, 2014. REUTERS/Brendan McDermid (UNITED STATES - Tags: BUSINESS POLITICS HEADSHOT) 

Former Russian tycoon Mikhail Khodorkovsky speaks about his "Open Russia" movement at the Council on Foreign Relations in New York October 6, 2014. REUTERS/Brendan McDermid (UNITED STATES - Tags: POLITICS BUSINESS) 

Former Russian oil tycoon Mikhail Khodorkovsky speaks during a news conference in Donetsk, Eastern Ukraine, April 27, 2014. Khodorkovsky attempted to talk to pro-Russian protesters in the eastern Ukraine city of Donetsk on Sunday but was stopped from entering the occupied regional administration building. REUTERS/Baz Ratner (UKRAINE - Tags: BUSINESS CIVIL UNREST POLITICS ENERGY) 

Former Russian oil tycoon Mikhail Khodorkovsky speaks during a news conference in Donetsk, Eastern Ukraine, April 27, 2014.
Khodorkovsky attempted to talk to pro-Russian protesters in the eastern Ukraine city of Donetsk on Sunday but was stopped from entering the occupied regional administration building. REUTERS/Baz Ratner (UKRAINE - Tags: BUSINESS CIVIL UNREST POLITICS ENERGY HEADSHOT) 

Former Russian oil tycoon Mikhail Khodorkovsky speaks during a news conference in Donetsk, Eastern Ukraine, April 27, 2014. Khodorkovsky attempted to talk to pro-Russian protesters in the eastern Ukraine city of Donetsk on Sunday but was stopped from entering the occupied regional administration building.
REUTERS/Baz Ratner (UKRAINE - Tags: BUSINESS CIVIL UNREST POLITICS ENERGY) 

Former Russian oil tycoon Mikhail Khodorkovsky (L) speaks with a member of a pro-Russian self-defence unit in the eastern Ukrainian city of Donetsk April 27, 2014. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Former Russian oil tycoon Mikhail Khodorkovsky (C) speaks with members of a pro-Russian self-defence unit in the eastern Ukrainian city of Donetsk April 27, 2014. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Russian former oil tycoon Mikhail Khodorkovsky (L) talks to participants of the "Ukraine-Russia: the Dialogue" congress in the eastern city of Kharkiv April 26, 2014. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS BUSINESS) 

Russian former oil tycoon Mikhail Khodorkovsky (L) talks to a member of the Ukrainian parliament and the former chairman of the Mejlis of the Crimean Tatars Mustafa Dzhemilev during "Ukraine-Russia: the Dialogue" congress in Kiev April 25, 2014. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS) 

Ukrainian tycoon and presidential election candidate Petro Poroshenko (L) talks to Russian former oil tycoon Mikhail Khodorkovsky (R), as former Ukrainian Interior Minister Yuriy Lutsenko stands nearby, during "Ukraine-Russia: the Dialogue" congress in Kiev April 25, 2014. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS ELECTIONS BUSINESS) 

Former Russian oil tycoon Mikhail Khodorkovsky speaks during the opening of the "Ukraine-Russia: Dialogue" congress in Kiev, April 24, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Former Russian oil tycoon Mikhail Khodorkovsky speaks during the opening of the "Ukraine - Russia: Dialogue" congress in Kiev April 24, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Former Russian oil tycoon Mikhail Khodorkovsky speaks during the opening of the "Ukraine - Russia: Dialogue" congress in Kiev April 24, 2014. REUTERS/Valentyn Ogirenko (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Former Russian oil tycoon Mikhail Khodorkovsky gives students a lecture on human rights and freedom in Kiev March 10, 2014. Khodorkovsky, who was widely seen as a political prisoner, was released by Russian President Vladimir Putin in December last year after more than 10 years in jail. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST EDUCATION) 

Former Russian oil tycoon Mikhail Khodorkovsky gives students a lecture on human rights and freedom in Kiev March 10, 2014. Khodorkovsky, who was widely seen as a political prisoner, was released by Russian President Vladimir Putin in December last year after more than 10 years in jail. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST EDUCATION) 

Former Russian oil tycoon Mikhail Khodorkovsky gives students a lecture on human rights and freedom in Kiev March 10, 2014. Khodorkovsky, who was widely seen as a political prisoner, was released by Russian President Vladimir Putin in December last year after more than 10 years in jail. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST EDUCATION) 

Former Russian oil tycoon Mikhail Khodorkovsky gives students a lecture on human rights and freedom in Kiev March 10, 2014. Khodorkovsky, who was widely seen as a political prisoner, was released by Russian President Vladimir Putin in December last year after more than 10 years in jail. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST EDUCATION) 

Former Russian oil tycoon Mikhail Khodorkovsky gives students a lecture on human rights and freedom in Kiev March 10, 2014. Khodorkovsky, who was widely seen as a political prisoner, was released by Russian President Vladimir Putin in December last year after more than 10 years in jail. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST EDUCATION) 

Former Russian oil tycoon Mikhail Khodorkovsky gives students a lecture on human rights and freedom in Kiev March 10, 2014. Khodorkovsky, who was widely seen as a political prisoner, was released by Russian President Vladimir Putin in December last year after more than 10 years in jail. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST EDUCATION) 

Former Russian oil tycoon Mikhail Khodorkovsky gives students a lecture on human rights and freedom in Kiev March 10, 2014. Khodorkovsky, who was widely seen as a political prisoner, was released by Russian President Vladimir Putin in December last year after more than 10 years in jail. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST EDUCATION) 

Former Russian oil tycoon Mikhail Khodorkovsky gives students a lecture on human rights and freedom in Kiev March 10, 2014. Khodorkovsky, who was widely seen as a political prisoner, was released by Russian President Vladimir Putin in December last year after more than 10 years in jail. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST EDUCATION) 

Former Russian oil tycoon Mikhail Khodorkovsky gives students a lecture on human rights and freedom in Kiev March 10, 2014. Khodorkovsky, who was widely seen as a political prisoner, was released by Russian President Vladimir Putin in December last year after more than 10 years in jail. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST EDUCATION) 

Former oligarch Mikhail Khodorkovsky speaks with wounded anti-government protesters at a hospital in Kiev March 9, 2014. Khodorkovsky, addressing thousands of people at the cradle of the uprising against Ukraine's Moscow-backed leader, accused Russia on Sunday of being complicit in police violence against protesters. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST TPX IMAGES OF THE DAY) 

Former oligarch Mikhail Khodorkovsky (R) visits a wounded anti-government protester at a hospital in Kiev March 9, 2014. Khodorkovsky, addressing thousands of people at the cradle of the uprising against Ukraine's Moscow-backed leader, accused Russia on Sunday of being complicit in police violence against protesters. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Former oligarch Mikhail Khodorkovsky addresses Ukrainians during an anti-war rally at Independence Square in Kiev March 9, 2014. Khodorkovsky, addressing thousands of people at the cradle of the uprising against Ukraine's Moscow-backed leader, accused Russia on Sunday of being complicit in police violence against protesters. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST ENERGY BUSINESS TPX IMAGES OF THE DAY) 

Former oligarch Mikhail Khodorkovsky waves to Ukrainians during an anti-war rally at Independence Square in Kiev March 9, 2014. Khodorkovsky, addressing thousands of people at the cradle of the uprising against Ukraine's Moscow-backed leader, accused Russia on Sunday of being complicit in police violence against protesters. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST ENERGY BUSINESS) 

Former Russian oil tycoon Mikhail Khodorkovsky (C) visits a wounded police officer at a hospital in Kiev March 9, 2014, a day before he gives students a lecture on human rights and freedom. Russian forces tightened their grip on Crimea on Sunday despite a U.S. warning to Moscow that annexing the southern Ukrainian region would close the door to diplomacy in a tense East-West standoff. Khodorkovsky, who was widely seen as a political prisoner, was released by Russian President Vladimir Putin in December last year after more than 10 years in jail. Picture taken behind a glass pane. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST HEALTH) 

Former Russian oil tycoon Mikhail Khodorkovsky (R) and Russian opposition activist Ksenia Sobchak visit Independence Square, cradle of the uprising against ousted President Viktor Yanukovuch, in Kiev March 9, 2014, a day before he gives students a lecture on human rights and freedom. Russian forces tightened their grip on Crimea on Sunday despite a U.S. warning to Moscow that annexing the southern Ukrainian region would close the door to diplomacy in a tense East-West standoff. Khodorkovsky, who was widely seen as a political prisoner, was released by Russian President Vladimir Putin in December last year after more than 10 years in jail. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Former Russian oil tycoon Mikhail Khodorkovsky (R) and Russian opposition activist Ksenia Sobchak visit Independence Square, cradle of the uprising against ousted President Viktor Yanukovuch, in Kiev March 9, 2014, a day before he gives students a lecture on human rights and freedom. Russian forces tightened their grip on Crimea on Sunday despite a U.S. warning to Moscow that annexing the southern Ukrainian region would close the door to diplomacy in a tense East-West standoff. Khodorkovsky, who was widely seen as a political prisoner, was released by Russian President Vladimir Putin in December last year after more than 10 years in jail. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Former Russian oil tycoon Mikhail Khodorkovsky visits Kiev, a day before giving students a lecture on human rights and freedom March 9, 2014. Russian forces tightened their grip on Crimea on Sunday despite a U.S. warning to Moscow that annexing the southern Ukrainian region would close the door to diplomacy in a tense East-West standoff. Khodorkovsky, who was widely seen as a political prisoner, was released by Russian President Vladimir Putin in December last year after more than 10 years in jail. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Former Russian oil tycoon Mikhail Khodorkovsky visits Independence Square, cradle of the uprising against ousted President Viktor Yanukovuch, in Kiev March 9, 2014. Russian forces tightened their grip on Crimea on Sunday despite a U.S. warning to Moscow that annexing the southern Ukrainian region would close the door to diplomacy in a tense East-West standoff. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Volunteers give a hot meal to Russian former oil tycoon Mikhail Khodorkovsky (L) as he visits Independence Square in Kiev March 8, 2014. U.S. Secretary of State John Kerry told Russian Foreign Minister Sergei Lavrov in a telephone call on Saturday that any Russian steps to annex Ukraine's Crimea region would close the door to diplomacy, a U.S. State Department official said. REUTERS/Alex Kuzmin (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Russian former oil tycoon Mikhail Khodorkovsky (C) speaks with members of the Maidan self-defense battalion during his visit in Kiev March 8, 2014. U.S. Secretary of State John Kerry told Russian Foreign Minister Sergei Lavrov in a telephone call on Saturday that any Russian steps to annex Ukraine's Crimea region would close the door to diplomacy, a U.S. State Department official said. REUTERS/Alex Kuzmin (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Russian former oil tycoon Mikhail Khodorkovsky (L) speaks with former Ukrainian Interior Minister Yuriy Lutsenko as they pass by a barricade in central Kiev March 8, 2014. U.S. Secretary of State John Kerry told Russian Foreign Minister Sergei Lavrov in a telephone call on Saturday that any Russian steps to annex Ukraine's Crimea region would close the door to diplomacy, a U.S. State Department official said. REUTERS/Alex Kuzmin (UKRAINE - Tags: POLITICS CIVIL UNREST TPX IMAGES OF THE DAY) 

Russian former oil tycoon Mikhail Khodorkovsky holds a book as he visits a library for members of the Maidan self-defense battalion in Kiev March 8, 2014. U.S. Secretary of State John Kerry told Russian Foreign Minister Sergei Lavrov in a telephone call on Saturday that any Russian steps to annex Ukraine's Crimea region would close the door to diplomacy, a U.S. State Department official said. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Russian former oil tycoon Mikhail Khodorkovsky speaks with former Ukrainian Interior Minister Yuriy Lutsenko during his visit to Kiev March 8, 2014. U.S. Secretary of State John Kerry told Russian Foreign Minister Sergei Lavrov in a telephone call on Saturday that any Russian steps to annex Ukraine's Crimea region would close the door to diplomacy, a U.S. State Department official said. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Russian former oil tycoon Mikhail Khodorkovsky (2nd L) speaks with members of the Maidan self-defense battalion during his visit to Kiev March 8, 2014. U.S. Secretary of State John Kerry told Russian Foreign Minister Sergei Lavrov in a telephone call on Saturday that any Russian steps to annex Ukraine's Crimea region would close the door to diplomacy, a U.S. State Department official said. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Russian former oil tycoon Mikhail Khodorkovsky (R) and former Ukrainian Interior Minister Yuriy Lutsenko hold painted helmets as they pose for picture in Kiev March 8, 2014. U.S. Secretary of State John Kerry told Russian Foreign Minister Sergei Lavrov in a telephone call on Saturday that any Russian steps to annex Ukraine's Crimea region would close the door to diplomacy, a U.S. State Department official said. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Russian former oil tycoon Mikhail Khodorkovsky (C) speaks with members of the Maidan self-defense battalion during his visit to Kiev March 8, 2014. U.S. Secretary of State John Kerry told Russian Foreign Minister Sergei Lavrov in a telephone call on Saturday that any Russian steps to annex Ukraine's Crimea region would close the door to diplomacy, a U.S. State Department official said. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Russian former oil tycoon Mikhail Khodorkovsky (R) speaks with members of the Maidan self-defense battalion during his visit to Kiev March 8, 2014. U.S. Secretary of State John Kerry told Russian Foreign Minister Sergei Lavrov in a telephone call on Saturday that any Russian steps to annex Ukraine's Crimea region would close the door to diplomacy, a U.S. State Department official said. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Russian former oil tycoon Mikhail Khodorkovsky (L) speaks with a member of the Maidan self-defense battalion as former Ukrainian Interior Minister Yuriy Lutsenko (C) looks on near a barricade in Kiev March 8, 2014. U.S. Secretary of State John Kerry told Russian Foreign Minister Sergei Lavrov in a telephone call on Saturday that any Russian steps to annex Ukraine's Crimea region would close the door to diplomacy, a U.S. State Department official said. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Russian former oil tycoon Mikhail Khodorkovsky speaks with a member of the Maidan self-defense battalion during his visit to Kiev March 8, 2014. U.S. Secretary of State John Kerry told Russian Foreign Minister Sergei Lavrov in a telephone call on Saturday that any Russian steps to annex Ukraine's Crimea region would close the door to diplomacy, a U.S. State Department official said. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Russian former oil tycoon Mikhail Khodorkovsky listens to a member of the Maidan self-defense battalion during his visit in Kiev March 8, 2014. U.S. Secretary of State John Kerry, speaking to Russia's foreign minister for the fourth day in a row, told Sergei Lavrov that annexing Crimea "would close any available space for diplomacy," a U.S. official said. REUTERS/Tatyana Makeyeva (UKRAINE - Tags: POLITICS CIVIL UNREST) 

Judges of Russia's Supreme Court attend a hearing in Moscow January 23, 2014. Platon Lebedev, the ex-business partner of former oil tycoon and Kremlin critic Mikhail Khodorkovsky, will be released from prison early under a ruling by Russia's Supreme Court on Thursday. REUTERS/Maxim Shemetov (RUSSIA - Tags: POLITICS CRIME LAW BUSINESS) 

Freed Russian former oil tycoon Mikhail Khodorkovsky (C) poses with his parents Marina and Boris, son Pavel (R) and his first wife Yelena (L) ahead of a news conference in the Museum Haus am Checkpoint Charlie in Berlin, December 22, 2013. Khodorkovsky on Sunday promised not to seek power in Russia but said he would fight for the freedom of people he considered political prisoners, challenging Vladimir Putin two days after a presidential pardon freed him from jail. REUTERS/Michael Kappeler/Pool (GERMANY - Tags: POLITICS) 

Freed Russian former oil tycoon Mikhail Khodorkovsky stands with his parents Marina and Boris ahead of a news conference in the Museum Haus am Checkpoint Charlie in Berlin, December 22, 2013. Khodorkovsky on Sunday promised not to seek power in Russia but said he would fight for the freedom of people he considered political prisoners, challenging Vladimir Putin two days after a presidential pardon freed him from jail. REUTERS/Michael Kappeler/Pool (GERMANY - Tags: POLITICS) 

Freed Russian former oil tycoon Mikhail Khodorkovsky (R) poses with father Boris and son Pavel (L), ahead of a news conference in the Museum Haus am Checkpoint Charlie in Berlin, December 22, 2013. Khodorkovsky on Sunday promised not to seek power in Russia but said he would fight for the freedom of people he considered political prisoners, challenging Vladimir Putin two days after a presidential pardon freed him from jail. REUTERS/Michael Kappeler/Pool (GERMANY - Tags: POLITICS)

Freed Russian former oil tycoon Mikhail Khodorkovsky (C) poses with his parents Marina and Boris, son Pavel (R) and his first wife Yelena (L) ahead of a news conference in the Museum Haus am Checkpoint Charlie in Berlin, December 22, 2013. Khodorkovsky on Sunday promised not to seek power in Russia but said he would fight for the freedom of people he considered political prisoners, challenging Vladimir Putin two days after a presidential pardon freed him from jail. REUTERS/Michael Kappeler/Pool (GERMANY - Tags: POLITICS)

Freed Russian former oil tycoon Mikhail Khodorkovsky (R) poses with father Boris and son Pavel (L), ahead of a news conference in the Museum Haus am Checkpoint Charlie in Berlin, December 22, 2013. Khodorkovsky on Sunday promised not to seek power in Russia but said he would fight for the freedom of people he considered political prisoners, challenging Vladimir Putin two days after a presidential pardon freed him from jail. REUTERS/Michael Kappeler/Pool (GERMANY - Tags: POLITICS)

Freed Russian former oil tycoon Mikhail Khodorkovsky stands with his parents Marina and Boris ahead of a news conference in the Museum Haus am Checkpoint Charlie in Berlin, December 22, 2013. Khodorkovsky on Sunday promised not to seek power in Russia but said he would fight for the freedom of people he considered political prisoners, challenging Vladimir Putin two days after a presidential pardon freed him from jail. REUTERS/Michael Kappeler/Pool (GERMANY - Tags: POLITICS)

Freed Russian former oil tycoon Mikhail Khodorkovsky (2L) poses with his parents Marina and Boris, and son Pavel (R), ahead of a news conference in the Museum Haus am Checkpoint Charlie in Berlin, December 22, 2013. Khodorkovsky on Sunday promised not to seek power in Russia but said he would fight for the freedom of people he considered political prisoners, challenging Vladimir Putin two days after a presidential pardon freed him from jail. REUTERS/Michael Kappeler/Pool (GERMANY - Tags: POLITICS)

Freed Russian former oil tycoon Mikhail Khodorkovsky stands with his parents Marina and Boris ahead of a news conference in the Museum Haus am Checkpoint Charlie in Berlin, December 22, 2013. Khodorkovsky on Sunday promised not to seek power in Russia but said he would fight for the freedom of people he considered political prisoners, challenging Vladimir Putin two days after a presidential pardon freed him from jail. REUTERS/Michael Kappeler/Pool (GERMANY - Tags: POLITICS)

Freed Russian former oil tycoon Mikhail Khodorkovsky stands with his parents Marina and Boris, and son Pavel (R), ahead of a news conference in the Museum Haus am Checkpoint Charlie in Berlin, December 22, 2013. Khodorkovsky on Sunday promised not to seek power in Russia but said he would fight for the freedom of people he considered political prisoners, challenging Vladimir Putin two days after a presidential pardon freed him from jail. REUTERS/Michael Kappeler/Pool (GERMANY - Tags: POLITICS)