This pie chart shows the different threats that can come from visiting Web sites that advertise unauthorized content.

(Credit: McAfee)

It's common knowledge that you can catch computer viruses on porn Web sites. But did you know it's also risky to surf the Web searching for free movies or music?

A study from McAfee to be released on Tuesday finds that adding the word "free" when looking for entertainment content in search engines greatly increases the chances of landing on a site hos...