Say it isnt so Banks....

rapper Lloyd Banks got locked up yesterday.

Canadian police picked up the G-Unit rapper for assaulting a local concert promoter.

What happened? Word is that Banks showed up to the club late, and when the promoter had the nerve to -- you know -- be angry about it, Banks went nuts. According to police Banks and three of his goons kidnapped the promoter. They reportedly took him back to his hotel room, where the beat and robbed him.

The promoter called the police when he was finally released and Banks and his three goons were arrested. All four men were charged with forceful confinement, aggravated assault and robbery.