[the_bear]

This is basically what Google's reCAPTCHA v3 does: https://developers.google.com/recaptcha/docs/v3

The other versions of recaptcha show the annoying captchas, but v3 just monitors various signals and gives a score indicating the likelihood that it's a bot.

We use this to reduce spam in some parts of our app, and I think there's an opportunity to make a better version, but it'd be tough for it to be better enough that people would pay for it since Google's solution is decent and free.