I received a message the other day from a gamertag "SHaDowX Sn1p3R" that told me to go to a certian website to get a modern warfare beta. Suspecting a "too-good-to-be-true" type of scam, I went to the site and noticed that it asked me to sign in to get the beta. Windows Live sites always say "Login" above the login boxes, not a long and drawn out description. The website poses as an xbox.com website - but there is no xbox.com/etc etc etc in the address bar. I also noticed that the xbox icon in the upper left doesn't lead back to xbox.com. Knowing it was a scam, I tried to avoid the player, only to realize that I couldn't send feedback. I filed a complaint immediately thereafter for feedback tampering.
So, this person is trying to get personal information through sign-ins to the website, and his gamertag is blocking feedback that anyone sends - good or bad.
I sent an email to the one listed here, and I hope this guy gets destroyed before he gets too many victims sucked in.