LA County sets up an anonymous e-mail service so you can tell someone you've given them an STD.
http://www.latimes.com/news/local/la...home-headlines
I don't expect this "service" to last long. See the attachment for an example "postcard." I sent one to a friend as a joke, but only after warning him first. This is going to be abused and a lot of people won't like the joke.