Killer phrase will fill your PC with spam

Researchers Ben Edelman and Hannah Rosenbaum reckon that typing the phrase 'Free Screensavers' into any search engine is the equivalent of lighting a blue touch paper and standing well back.

For a list of other danger words, read the article. The article mentions SiteAdvisor, which comes in a free version. I recently started using it and so far I've seen no downside to it except like all tools it may give a somewhat false sense of security if you don't use your brain along with it.