REUTERS/Mike Cassese
Activist shareholder William Ackman of Pershing Square Capital Management speaks during the Canadian Pacific Railway Ltd. shareholders and analysts meeting in Toronto February 6, 2012.
Allergan has already filed suit against both Ackman and Valeant for insider trading. It alleges that Ackman and Valeant violated specifically SEC rule 14 e-3, which has to do with making tender offers for companies based on or while knowing material non-public information.