Damn dude that's pretty depressing. Maybe her boyfriend was just PLAYING ONLINE GAMES?? I mean the point of most games is to virtually kill other players, playing some pranks seems pretty mild in comparison
There's a spectrum for sure. Past a certain point, when you're constantly bullying one person repeatedly and stalking them, it becomes harassment, even if it's in-game.
The real question is, are you generally trolling cause it's hilarious, or are you trying to bully individual people? It's tough to tell.