So, I was just watching the local news and there was a story about an internet site that would send an email to a person informing them that one of their previous sex partners has an STD. The person with the STD is never mentioned; it just says one of your former partners has an STD.
The name of the site is Inspot.com
This is some seriously ****** up ****. You can send greeting cards to your ex-partner that has some ****** up saying, like "It's not what you brought to the party, it's what you left with."
Beyond that, since it is anomymous, some seriously horrible practical jokes can be made. Sending someone a fake little message would cause some serious damage.