Sullivan St. is where Gigante hung around. The FBI who watched the place use to have this technique that was part psychological warfare and part practical joke. They'd have an agent put a paper bag over his head, kinda like Igor Gouzenko, and drive by the club as if an Informant was pointing out people and naming names.

Its an old and tested theory that when a criminal reacts in fear or under pressure, he slips up.

Didn't really work with the calculated Gigante.