What's the Point?

I've been playing a ton of bullet chess lately, and I haven't been exchanging any messages with any opponents - just playing them and moving on, often not even noticing what they're screen names are.

Recently I received the following nasty-gram from a player whose screen name is UJustGotTr0lled:

"Thanks for the super easy win.  However - I suggest you change your name to RandomPutz instead... get it???! Study up and I'll give you another free lesson soon. "

I had never said anything to this person, and I don't even remember playing him. (I use the male pronoun because females aren't usually such testosterone-fueled turds.)  I have no doubt I gave him an easy win, as I've been playing some pretty crappy games.  I'm just wondering what compels someone to post a message like this? I never provoked him. Did I beat him in a previous game, such that he was sore about it? Did someone beat him really badly, so that he got angry and decided to take it out on me?  It's strange behavior - insane, really.

Anyone else receive vicious messages like this for no ostensible reason?

Wondering.  Thanks for any insights, and have a great day.

Low self esteem. Sneering at random people on the internet boosts his fragile ego.

Not really, sounds like a little light-hearted ribbing OP has decided to get offended by ergo establishing his virtuosity, which would suggest OP has the fragile ego.