Mischief, Incorporated was a criminal organization that ceased operations in 1967.
While infiltrating the Dumas Tower, Cate Archer overheard two Dumas Industrial Enterprise guards talking about how shocked they were that Mischief, Incorporated had just shut down. Apparently this organization had earned some admiration from some of the members of the criminal industry. Their exploits had made for great headlines including one caper that dealt with a penguin suit debacle.
Troy, another guard at the tower, did not feel any remorse for Mischief, Incorporated going out of business. Stating that niche orientation and lack of big exploits would lead to a natural demise of a criminal company. This caused a fellow guard, Simon to hit him so hard it knocked out a tooth.