Apple should "ignore" David Einhorn and Greenlight Capital, according to Warren Buffett. Speaking with CNBC today, the famous investor and Berkshire Hathaway CEO dismissed Einhorn's push for a preferred Apple stock option, which recently led to a threatened lawsuit. Greenlight ultimately withdrew the suit, since its only goal was to prevent a vote on proxy proposal at Apple's annual shareholders meeting, for which a judge granted the needed injunction.