Former pharmaceutical boss Martin Shkreli, who was condemned last year for raising the price of a life-saving drug by over 5,000%, appears in front of Congress on Thursday but refuses to answer any questions. Shkreli – who can be seen making several faces while members of Congress are speaking but repeatedly invokes his fifth-amendment right to avoid giving evidence – later sent a tweet calling the politicians ‘imbeciles’. Shkreli’s company bought the rights to the drug Daraprim in September and immediately increased the price per pill from $13.50 to $750