Wholesome Greentext

People host private WoW servers, and some have 2x/3x/4x XP rates and altered drops and stuff like that.

I've never heard anyone say it's dangerous but I suppose the fear isn't unfounded. They generally run on outdated clients that wouldn't have the same level of security as retail, and then there's torrenting your client in the first place...

There's some really cool ones out there, though, and I'd recommend trying them if you want a free way to experience WoW again. There's one called Ascension where your character is all of the classes at once and you can get really creative with different builds.