Topic on Extension talk:ConfirmEdit

hCaptcha looks a lot like reCaptcha, but is newer and less-widely used. Cloudflare is one provider which switched from reCaptcha to hCaptcha, for example. It is not impossible to get bad data past hCaptcha - presumably by brute force attacks which can easily push your site above the one million hits per month limit for hCaptcha's "free" plan. This has been an issue since at least mid-2022. At that point, you will be approached in e-mail by hCaptcha marketers attempting to sell a very expensive "enterprise" version of the service, right around the time that you're dealing with increasing numbers of spam posts making their way past the blocks. That said, the majority of automated "spambot" posts will be blocked by hCaptcha; far less rubbish gets past hCaptcha than past reCaptcha, given that the latter's widespread adoption has made it the tool against which most of the spammers now appear to be testing their wares. As most of the "brute force" attacks seem to be coming from a long list of known problem IPs (the least-expensive cleantalk.org blacklist has about 10,000 records of spam records with frequency >= 200, for instance) it's probably best to use other means to block known-bad IPs from accessing your site at all, sending only whats left through hCaptcha. Otherwise, spammers will keep trying random responses until a small fraction of the spam gets through. The article does need to indicate that, while a bit more effective than reCaptcha, hCaptcha is vulnerable to determined attempts to get bad data past - the same as everything else. It's one tool in the toolbox, but it's not a panacea.

Actually, it's been going on a bit longer than that. I'm seeing spam posts with mid-2021 dates and (hCaptcha) in the edit comment, so apparently the spammers already were testing against hCaptcha.

Most of the brute-force attacks seem to be coming from IPs which are already one one or more of the real-time blacklists, so firewalling out the known-bad traffic first, then using CAPTCHA to sort what's left is likely best. Otherwise, what's to stop the spammers from hitting your server with two or three million attempts per month, which will exceed hCaptcha's limits for non-commercial use and which will also severely degrade operation of your server for human users. 204.237.89.128 21:46, 27 April 2023 (UTC)