pup: Potentially unwanted program. It is a message I get from my anti-virus software.
http://vil.nai.com/vil/pups/configuration.aspx
Just curious if you googled those potentially dangerous searches that are the subject of this thread, what would happen on your computer. Maybe you are just visiting very 'safe' sites and your anti-virus software works fine. I am surprised you don't get pop-ups from some of the attachments on FR.
You don't want to be too naive about viruses either. My son, the computer guru showed me all kinds of (benign) programs such as adware that was resident on my hard drive. They are not viruses per se, but how did they get there. The definition of a "virus" is often different for different people, too. "Virus" doesn't have to mean invasive and harmful to the computer.
I don't consider myself naive - my job every day is programming on computers, so I consider myself pretty savvy. I know a lot more than your average joe, anyhow. But I do think that a lot of people engage in activity that puts them at risk without knowing specifically which things they are doing that are risky. And if someone hasn't ever looked at their security settings in their browser, they are probably putting themselves at risk too.