By Joseph Menn SAN FRANCISCO (Reuters) – A heavily anticipated talk on how to identify users of the Tor Internet privacy service has been withdrawn from the upcoming Black Hat security conference. A Black Hat spokeswoman told Reuters that the talk had been canceled at the request of lawyers for Carnegie-Mellon University, where the speakers work as researchers. A CMU spokesman had no immediate comment. (Reporting by Joseph Menn; Editing by Chris Reese)