Penn & Teller did a whole show about the hysteria. Turns out that the test toilet seat was cleaner after a day's use than door handles and keyboards, and that the test subjects bare asses and genitals were cleaner than their hands and mouths.
Its hilarious to see people get all nuts over bacterias.
A new co-worker at my husband's job proclaimed to the owner of the company that she trys not to go into men's cubicles because they touch their privates when using the bathroom and don't wash their hands afterward--as if women can't be gross too.