Activist investors launched a record 508 campaigns against US companies last year, according to Thomson Reuters data, targeting names such as DuPont, General Electric, and AIG. The actions of certain activist hedge funds, however, has also attracted the attention of politicians, including Democratic presidential candidates Hillary Clinton and Bernie Sanders. Mr Ackman was one of the Valeant Pharmaceuticals International Inc officials who recently appeared in front of a Congressional committee to address the massive price hikes Valeant issued on some of its drugs. Valeant, a drug company whose creation was led by activist hedge fund ValueAct Partners, is under federal investigation for its use of specialty pharmacy companies. Politicians have targeted activists for being short term investors, at the expense of longer term shareholders.