Let's raise our game on chess.com
Maybe some Chess.com de-sensitivity training? Generally, I run across idiots every once in awhile but especially with a heckling winner or loser it's important to brush it off. It's self discipline and instead of avoiding it it is better to learn how to deal with those people for when they do come around. Besides, how difficult would it be to ban everybody who has ever run down a clock or said something offensive from losing their temper.