Once again, all trails lead back to you providing some alternative solutions instead of the empty catharsis of coming up with downsides to something in an internet comment.
Here's one of my own: Isn't it annoying that spambots show up the second I launch a website? Ugh! Well, got that out of the way. Now I need a solution.
What's yours?
It's not about disliking anti-spam measures, it's about highlighting the woeful method that is re-captcha.
"Select all squares with street signs" shows a bunch of squares, some of them contain only part of the pole that presumably has a sign attached out of shot. So do you click that square that only has the pole? A pole is not a sign, it's a piece of steel. But it's part of the sign, so are people expected to select it or not?
Re-captcha is not a smart system.
Guess we can close the file on that one.
Nobody is claiming it's perfect. But notice how nobody here is analyzing why people use ReCaptcha in the first place nor providing alternatives.
If you knew nothing of ReCaptcha and only read these comments, you'd wonder if it was a gag website operators put on their website for self-amusement, which is basically how I looked at homework as a kid. But I feel like this discussion is a bit more one-sided than I expected on HN, a place where I would've thought more people had experience running a website and how immediately effective ReCaptcha was the second you added a <textarea>.