A form of online forgery in which a troll or spammer uses your email address to subscribe you to numerous sites you don't recall signing up for in the first place.
They do this to spam up the email accounts of their victims and humilate them online, often to some kind of sick fetish site or the like.
"Hey Dan...I didn't know you signed up for sissy kiss."
"What? I don't recall signing up for that site at all."
"You must have fallen victim to a case of email hackering."