That's nasty. I know from experience;

A few years back I went to see a film(movie) at the local cinema(theater) with one of my best mates(buddy). While we were waiting we noticed the free postcard stand - basically adverts that could be used as postcards. Well, amongst those cards were also military recruitment cards that could be used to request information packs about joining the military. So we sent in three cards, one for each of the services, in the name of a mutual friend, and promptly forgot about it.
A few weeks later, the mutual friend starts receiving his two inch thick recruitment packets and mentions this to the first friend, who denies all involvement and offers up my neck for the chop.
I then discovered that the mutual friend had a tendancy to take things a bit too far, ie beyond a joke, when he spent most of a Sunday filling in every coupon he could find in every Sunday newspaper in my name. For the next year I was plagued with junk mail. If had lived in my own place I wouldn't have cared too much about it, but I lived with my parents at the time and they were none too amused. It really didn't help that several packages were things like commemorative plates and junky framed artwork that the companies thought that I had ordered, and needed to be dealt with.
My parents still haven't forgiven him.