Some other dictionaries list that sense, too. For example, Chambers (the 11th edition) has this: "intransitive verb To make a conscious attempt to provoke controversy or disagreement on the Internet", Merriam-Webster's Advanced Learner's Dictionary says “a person who tries to cause problems on an Internet message board by posting messages that cause other people to argue, become angry, etc” for troll,
Cambridge Advanced Learner's Dictionary says “to leave an insulting message on a part of the Internet for no reason”, and NOAD has "send (an e-mail message or posting on the Internet) intended…