All John Clifford wanted was a peaceful ride to work on the 7:39 to Pennsylvania Station. He would get to the Long Island Rail Road station at Long Beach early every weekday morning, board the train, stake out a five-seat section to rest his bad back, and prepare to read his newspaper and eat his breakfast.

But all around him, there would be chaos. One woman putting on full makeup while listening to her iPod and talking to friends. Another inviting guests to a barbecue and talking about personal problems. Men chatting on cellphones. They were treating the ride as a social situation, he testified in court on Tuesday, forming cliques and getting to know each other by name.

He asked the passengers to keep it down, but the chatter continued. In March 2007, Mr. Clifford had had enough. He shouted an obscenity at a passenger talking on his cellphone and slapped the hand of another, and was arrested. On Tuesday, he found himself in Manhattan Criminal Court, telling his tale.

“I stand up for my right to be let alone,” Mr. Clifford, a retired New York City police sergeant, declared from the witness stand at his nonjury trial on charges including harassment and assault.