Organizers of Sunday's Hot 97 Summer Jams concert had a novel way to deal with performers who went over their time limit: They shut off their microphones. Gucci Mane and Funk Master Flex both left the New Meadowlands Stadium stage gracefully after getting the hook, but the same can't be said for Ludacris. "He kept rapping a cappella when they cut off his juice," says a fan. "Finally, they decided to turn it back on. There really wasn't any other choice, because he wasn't getting off the stage."