In a civil lawsuit filed in federal court in California, Allergan said Ackman’s Pershing Square Capital Management and Valeant “hatched” an “improper and illicit insider-trading scheme” that allowed the hedge fund to buy Allergan shares, knowing about Valeant’s planned $51 billion takeover bid. Valeant and Pershing Square said the complaint was intended to prevent them from calling a special meeting of Allergan shareholders to vote on their board nominees.