On Nov. 9, Ashton Kutcher found himself on the receiving end of an 8 million-strong backlash after posting an indignant tweet about the firing of Penn State football coach Joe Paterno. Seems the "Two and a Half Men" star hadn't taken the extra 30 seconds to find out why Paterno had been sacked (child sex-abuse scandal).
"How do you fire Jo Pa?" Kutcher railed. "#insult #noclass as a hawkeye fan I find it in poor taste." What made his observation even worse: The actor, along with wife Demi Moore, fronts a charity to stop child exploitation.
Ashton's damage control was swift and severe. He handed over his Twitter account to his managers and issued a mea culpa. "My sincere apologies to anyone who I have offended," he said. "It was a mistake that will not happen again."
But Kutcher is hardly the first star to backpedal after an embarrassing incident. Click through to see some other mistake-making celebs who have been forced to chow down publicly on a big slice of humble pie ...