I would take "labrocca" advise above.

Although i would consider getting an IP trace on him, If you were to confront him over the phone, I would bet he would stop.

I had a similar problem a few years back, The person pissed me off to the point, that i actually found out where they lived, I called em, told em i may just come knocking on their door, told them their own address over the phone, The BS stopped right there.