While not exactly the completion of a dare, something along the same lines that has me a little worried.
A female friend (not really a "girlfriend") was staying with me for a few weeks this past summer, and we had gotten a little drunk. At some point, we turned on my webcam, which can see my bed, and were fooling around for a bit.
She said that I could keep the video, only if I gave her a copy, so I did.
She passed away in her sleep a couple weeks ago, and now here parents are in posession of her computer, which, as far as I know, still contains the video.
I'm really hoping that she deleted it, or that they never find it if she didn't. :/