I just witnessed this the other day. My sister must have installed something bad. I began to receive Yahoo IMs from her, once every 5 minutes or so, with a link in it. I knew better than to click on it, because I have read all of the horror stories in here and because it did not sound like it was something she would write. I tried to respond to her when the messages came through, but she did not reply. I finally called her because I realized what was going on. She ended up getting the virus uninstalled using Norton. Everyone should probably mention this to their family and friends who use Yahoo and other IM services that if they think a link someone sends them sounds fishy, to verify it with the sender before clicking on it.