Trudeau had been held in contempt by U.S. District Judge Robert Gettleman after the judge's in-box became jammed with more than 300 messages in about 36 hours after a post on Trudeau's Web site. The site gave Gettleman's e-mail address and urged supporters to tell him how Trudeau's hair- and weight-loss treatments had improved their lives.
The ruling by the 7th U.S. Circuit Court of Appeals found no reason to punish Trudeau. The panel of three judges said Gettleman's ruling was "an abuse of discretion," the opinion said.
Kimball Anderson, an attorney for Trudeau, said his client believed "he has been properly exercising his First Amendment right and that he did nothing wrong."
Trudeau did not intend to impede the judge's computer communication and was not in the judge's presence as e-mails were sent and therefore could not be held in contempt, Anderson argued.
The e-mail messages to Gettleman disrupted court communications and prompted a review to determine if the judge was in danger, the contempt ruling said.
"Leave (K)evin and his right to free (speech) alone. I wish (k)arma on your soul this very moment," court documents quoted one e-mail to the judge as saying.
Gettleman has presided over a case involving the Federal Trade Commission and Trudeau's treatments for hair and weight loss.
Gary Feinerman, an attorney for the judge, declined to comment.