cross posting off an email...
My crazy idea so far.
Basically everything the guy does on the internet is not what it seems and comes to bite him at the same time. The girl he IMs is underage when he meets her in person. The person his flame warning with on the book fan forum is the author who is really a vampire and wants to kill him for the flaming, and is also the 'underage' girl (really 700 years old) and in love with his other screename for a fanfic he wrote (as a joke) that made her think he really could understand her. The thing he bought on email is a magical item of dangerous power and the ancient society wants it back. The game he plays is a training ground for a alien space fleet. The fleet wants to hire him and the enemies of the fleet want to kill him since the game has been real and he has been slaughtering them. The email scammer he was playing along with for kicks is real and has power enemies that try to kill him. Etc. oh, and an evil overlord wants to take him out (or ally with him) because the gag site he put up was too realistic.