The number of things that are "wrong" with reCatcha etc, have been mentioned on here ad nauseam. In fact, I'll quote myself from another debate on the subject, a while back:

  >1: It's never made clear exactly what you're supposed to click on. For example. If I'm told to click on "traffic lights" does that mean just the lights?... or the poles as well?... and what about a square that only has a tiny bit in it? Does that count too, or is it only squares which are mostly filled by the object in question?

  >2: They make no concession to non-US English speakers. I've been asked to identify things before, where I had to guess what the word means because the same thing is called something completely different in UK English.

  >The only thing that approaches the level of rage that reCaptchas instil in me are those captchas where you've got to transcribe what's in a photo of some letters & numbers and where they NEVER fecking tell you whether it's case sensitive or not, or where they use identical characters for zero and letter O, one and letter I, etc.