True Shevron, but most people install crap in the spur of the moment.
"because i needed a driver and couldn't find it anywhere else, and it installed this and that"
"I have mistakenly clicked agree on a webpage toolbar installation"
"I went to this website" (crawling with viruses and malware)
"I received it from a friend on the email" (scams and hacks into emails)
Those are some of the reasons people do get this crap