This morning, we had the return of quite an aggressive spambot this time to Decks, creating tens of thousands of courses, which has previously caused site performance problems for the whole of Memrise.
We’ve just deployed the addition of a reCaptcha “I’m not a robot” button on the course creation page.
Hopefully it works well and isn’t too intrusive.
We had already done the work of reviewing lots of options for captchas, and this was by far the one with the best user experience, and which was the easiest to implement. Also we’re confident Google will update it as attackers alter their behaviour.
Apparently it won’t work in mainland China, because the whole reCaptcha service is blocked. If this is a large problem for Decks users, we can revisit it, but felt it was more important to keep the site up and working for most users in the short term.
Please let us know if you have any problems!