One of the alleged gang members arrested outside a San Francisco courtroom for what the the District Attorney's office describes as an act of witness intimidation has been charged with violating the terms of his probation on a past felony conviction. He could return to prison as a result, the man's lawyer said today.Intimidating.John Brown is the only one of the seven men who has been formally charged since the arrests took place on Oct. 6. DA office spokesman Brian Buckelew said that prosecu