Office workers of German airline Lufthansa display a placard reading "We are real Lufthanseatics, and you?" as they protest against the Lufthansa pilot's strike at Fraport airport in Frankfurt April 2, 2014. Lufthansa pilots started a three-day walkout on Wednesday, effectively grounding Germany's largest airline in one of the biggest strikes ever to hit the company. Lufthansa has cancelled 3,800 flights during the strike, which runs until the end of Friday, and says the strike will cost it tens of millions of euros. The pilots are striking to demand that Lufthansa reinstate an early retirement scheme . REUTERS/Kai Pfaffenbach/Files (GERMANY - Tags: BUSINESS EMPLOYMENT TRANSPORT CIVIL UNREST)