One News.com story that really hit home for me today was "Yahoo IM users get more than they bargained for" (http://www.techrepublic.com/2100-1035_11-5845886.html). According to the article, "By accepting Yahoo's 'typical' installation of YIM with Voice, it will also download Yahoo's Search Toolbar with anti-spyware and anti-pop-up software, desktop and system tray shortcuts, as well as Yahoo Extras, which will insert Yahoo links into the Internet Explorer browser."
I don't know about you, but I don't touch the "customized" installation feature with a 10-foot pole, because that's usually where all that extra junk lives. Yes, I accepted the "typical" installation, and after a while, I started to notice that there were some strange additions, such as an extra popup blocker and a Y search icon when I highlighted text. However, I wasn't exactly sure what was going on until after I read this article. Sneaky stuff, Yahoo!! Just an FYI - I uninstalled the entire thing and reinstalled with the "customized" feature, which allowed me to deselect those unnecessary extras.