A prototype of Acumulus9's wearable camera QuidredCam (L) is shown during the Mobile World Congress in Barcelona March 1, 2015. Ninety thousand executives, marketers and reporters gather in Barcelona this week for the telecom operators Mobile World Congress, the largest annual trade show for the global wireless industry. REUTERS/Gustau Nacarino (SPAIN - Tags: BUSINESS TELECOMS SCIENCE TECHNOLOGY)