[t0lk]

I have a mediawiki wiki and let me tell you there are tons of old spam bots out in the wild, ones that would fail at the presence of any captcha. Come to think of it, I've experienced most generations of spam bots since I started. With no protection I'd get spam links/registrations every day. With a simple question like 2+2=? I'd get one every 3-4 days or once a week and with reCaptcha I'd get them a little less frequently. I had to switch away from reCaptcha a few years back however when it appeared to no longer prevent spam (people are paid to solve them all day, etc).