Actually, in US too. No, I'm serious!

The technique it's called Mechanical Turk, and its first form is developed by Amazon.com. The process is quite simple:
1) A large number of humans are going to that site.
2) They will be asked to do some work.
3) After completion, they will get paid in their Amazon.com account.

Web services can "use you" in this way:

 read (photo);
 photoContainsHuman = callMechanicalTurk(photo);
 if (photoContainsHuman == TRUE) {
   acceptPhoto;
 }
 else {
   rejectPhoto;
 }

Now, assuming that a "critical mass" of people are working for Amazon in this way, the whole scheme will work. Brilliant, isn't it?

Which makes me thinking: lately, we've seen the emergence of a new economic model - do some small stuff, and get paid. A similar technique in this respect is AdSense. Who knows whether this new ways to get money won't displace more traditional ways. Like... getting salaries?