I bought my first empeg from a guy in America. The only recourse I had originally was a university email address, which I thought would be enough. I ended up doing a Google search with the guys name and found his webpage on the university web server. This was great because not only did it show his postal address, it also listed who his college room mates where, and what his final project was.
Looking back I'm surprised I was that trusting, I suppose I was so desparate to get an empeg I would have done almost anything (carplayer didn't come along for another month or so).