Snow, get an <a href="http://www.beyonddesign.net/pub/software/ICQ98A.EXE">old version</a> of ICQ, then use a <a href="http://www.cse.unsw.edu.au/~kleu074/icq.html">crack</a> that does not follow the ICQ protocol entirely. This will allow you to add this guy to your ICQ without his authorisation, and get his real IP. With his IP, you can find out who the ISP his, then ask your lawyer to write to them and ask for his identity. Identity thef is a serious crime.
Don't ask me for help in doing this, as it might well be illegal, and I don't use that version of icq.
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