The inexplicable accumulation of free toolbars on a rarely used browser (usually Internet Explorer) that obscures most of the screen when you open a window.
This is caused by programs that make money by including toolbars with their software (like Yahoo Messenger) which takes advantage of people too lazy to read the installer.
Friend using their other friend's computer: Geez, why do you have so many toolbars on your browser? I can't see!
Other friend: Oh, yeah, that browser has some toolbar mold I haven't cleaned up yet. Use Chrome or something.