They claimed to have a working product and a big list of paying clients while in fact they had a half-assed prototype written by one hapless dude who they paid to the tune of $15 an hour. Which i helped to transform into a somewhat-better prototype and they paid very well for it. But no actual paying clients ever existed and the idea was obviously brain-dead from day one. After they got tired of pretending, they stopped paying, then disappeared. Then years later i read in the news that subsequent investors launched an investigation into fraud and they were put on the list in some countries.

I'm sure no one except themselves ever made any money on it, certainly not YC.