MSN Attacks!

For the last week I have been flooded with requests from random people I don't know to add me to their contact list. I find it unlikely that I have been infected with some sort of worm/virus since I use Linux. The people who try to add me are real and they seem just as confused as I am on why they added me to their list. I have started denying anyone who tries to add me, which is annoying since I can't tell which requests are legitimate.