My Gamertag is identical to my forum nick in most of the european gaming and movie forums I participate in. I've been using this nick since the advent of DVD 1996/97 so it's quite possible to meet me in different places.

HOWEVER, apparently there are a couple of people out there who use this nick as well, examples:

eBay - not me
Yahoo Instant Messener - not me as well...
Some US forums - not me

What I'm trying to say is that I used this nick for a long time (for private purposes only) and I will continue to do so - but I have no grudge against someone who used this nick on a forum where he registered before me.