[revorad]

From the first footnote on that blog post, this has got to be the best non-computer hack I've read so far:

One of the Y Combinator questions asked you to name one non-computer system that you’d hacked in some interesting way. My answer concerned a man-in-the-middle attack I once did on Craigslist personals. I placed an ad as a woman seeking a man, and as a man seeking a woman, and then simply crossed the email streams by forwarding mail from one to the other, and vice versa. Most Craigslist personals didn’t even have photos back then, so the switch went undetected, even after the couples had met. I handed off the relationship by telling one that the other’s email address had changed, from my fake one to the real one, and likewise vice versa. For all I know, those couples are still together and having kids. They probably don’t know to this day what happened or what brought them together.

[abbasmehdi]

I hate to be a killjoy but neither party ever asked why the e-mail address was changed resulting in the other one jumping in and saying "I never changed my email address, you changed yours!!"? And thus opening up an investigation as they show each other the emails from the past. Secondly, neither party ever asked "Was this the first time you posted an ad on craigslist?" and finally neither party ever said "I don't usually respond to ads on craigslist but..." (people say this out of insecurity not because they actually mean it, this is just to make themselves look good).

I know this because I use to do this all the time in college over skype , record long awkward conversations between distant aquaintences and roll on the floor laughing daiwa try to figure out who called whom and who they are. This was actually a lot of fun, it was an exercise in psychology, we would try to predict how crazy explosive weird conversations could get and see what happens based on people's personality profiles.

My point is that they would have to be really really stupid to not know that somebody else connected them...