They did not tried if this works though. I mean the team that implemented the new Google captcha won't be that dumb. They would have known this as a flaw..
Assuming people have written secure code because they're the kind of people who wouldn't make a mistake is a sucker bet.
Our post was inspired from yours. We have added to the link to your original blog post now. Good one!
Updated here: http://www.shieldsquare.com/blog/sorry-google-captcha-recapt...
It's not exactly a copy-paste though.
This is wrong. Try posting a few times in 4chan, even if it recognizes you as a human, after posting a bit more it will ask for the captcha anyway.
As for a bot getting a human to "seed" it, there isn't much they can do aside from throttling the rate of automatic passes to once every 20 seconds or so. They could tune that parameter to balance between usability and bot detection.