Can you find person by description?

Ok, we had a dinner yesterday and started to talk about internet and how did it change our lifes and how fast it keeps on progressing. Every day there is something new that you didnt even think human`s mind can come up with.Then we starting to talk about networking and people search. Several years ago it was really hard to locate a particular person and now you can find somebody by little details, such as vacation time, hotels they were staying, commun - s, clubs, interests etc. One of my friend suggested that its even possible to find a person by description only! I disagreed. I really dont think that you can do it, but then again thinking about that whole innovation stuff i decided to ask - may be there is already a resourse that i don`t know, that actually allows it? Thanks!