Activists heat up board rooms more than you think By: CNBC.com News May 09, 2014 at 07:00 AM EDT Activist investors are known to make headlines, but surprisingly only a third of the firms that are approached by activists make the overtures public. Read More >> Related Stocks: Apple BlackRock Citigroup Evercore Partners Inc Herbalife Ltd Legg Mason Morgan Stanley Twitter, Inc. Valeant Pharmaceuticals International, Inc.