It seemed like a promotional slam dunk for Woody Harrelson: take part in the “Ask Me Anything” online chat series on Reddit, the social news site, and write some funny answers to questions from fans.

But then citizen celebrity journalists attacked. “The mistake Harrelson made,” said Melissa Knowles of Yahoo, “was that he thought he would just be promoting his new movie, Rampart.”

In the movie, Harrelson plays a dirty Los Angeles cop nicknamed “Date Rape Dave,” a moniker whose meaning is two-fold, Jake Coyle of the Associated Press pointed out. But instead of being asked a question about his fictional character, he found himself faced with queries about his real-life transgressions. One Reddit interviewer with the username AndyRooney asked:

I went to a high school in LA and you crashed our prom after party (Universal Hilton). You ended up taking the virginity of a girl named Roseanna. You didn’t call her afterwards. She cried a lot. Do you remember any of this and can confirm or have you been so knee deep in hollywood pooty for so long that this qualifies as a mere blip?”
Harrelson flatly denied the accusation and tried to steer the conversation back to Rampart. His publicist even took over answering some questions. But it was too late: the interview quickly devolved into a hate campaign against Harrelson.

Forbes used the occasion to school “high-profile folks” on the do’s and don’ts of social media Q and As. “Authenticity,” Kashmir Hill wrote, “goes a long way in pleasing the social media audience.”