I usually ignore Ignorant people who insult others playing on-line Poker, as they get some kind of pleasure from trolling others and if you show that it gets to you it just encourages them to carry on and do more.
Some times they do it in order to put you on Tilt and try to win games the only way they know how to and get you annoyed so you will lose by making bad decisions.
You usually find they are very lonely, sad individuals and because they cannot find something good or Intelligent to say about someone, they resort to insults because it is the way they have been treated in the past by their parents or teachers or even someone in a higher position at work, and they do not have the guts to say things to them, so they take it out from the safety of their own tiny little World that no one can get to them and they think they can say whatever they want.
Ignore these sad, tiny, mindless individuals and they will eventually crawl back into the holes they came from.
When the fun Stops, STOP!