As described here, Kenzero is a diabolical Trojan virus that blackmails Internet porn users with their browsing histories. As described in the linked article from The Telegraph it enters a computer when a user downloads sexually “explicit Hentai anime” (Googling the term was as far as I wanted to go). It then activates,
popping up an installation screen that prompts the computer user to type in personal information. The virus then takes screengrabs of a user’s browsing history, and publishes a list of all the sites they have visited online. A dialog box or email is then sent to the user, demanding a credit card payment of around £10 to remove the list from the internet.
The article does not say whether those responsible for the virus actually remove the incriminating browsing history. Two morals: keep your virus software up-to-date, and if downloaded porn asks you for your name, just say no.