Ironically its now easier for robots to solve Google Captchas than it is for humans, as evident by the browser extensions that solve them that exists.
I used to have a lot of bot spam, but then I mostly foiled them with the world's silliest captcha. Looks like a math problem, but the solution isn't what's required to proceed.
AFAIK most of those just pay a human in a low income country.
I used to have a lot of bot spam, but then I mostly foiled them with the world's silliest captcha. Looks like a math problem, but the solution isn't what's required to proceed.