Ms Ani90 was on this flight and they were puzzled as to why it was diverted when they were less than an hour from EWR (the flight at that point was scheduled to arrive almost an hour ahead of schedule). The offending passenger was restrained in handcuffs, and had been for the last 2 hours or so of the flight, and while still belligerent was restrained in the rear and (presumably) not a direct threat to the aircraft. Apparently, the altercation was a man having a big fight with his girlfriend. Are aircraft preferentially directed to certain airports when such threat exists?