I doubt you can ever be fully stop bots. The only way I can see to significantly reduce bot is to make everyone pay a one off £1 to sign up and force the use of a debit/credit card, no paypal, etc. The obvious issues are, it removes annonimity, and blocks entry.
Possible mitigations;
Maybe you don’t need to keep the card information after the user pays for sign up?
Signed up users can be given a few “invite codes” a year enable those who don’t have the means to pay the £1 to get an account.
You can just get rid of the whole payment thing and go with invite codes alone. Of course you’ll be limiting registration speed massively (which may not be good depending on if you’re in the middle of a Reddit exodus or not), but it is mostly bot-proof. Tildes seems to have pulled it off.
I doubt you can ever be fully stop bots. The only way I can see to significantly reduce bot is to make everyone pay a one off £1 to sign up and force the use of a debit/credit card, no paypal, etc. The obvious issues are, it removes annonimity, and blocks entry.
Possible mitigations;
You can just get rid of the whole payment thing and go with invite codes alone. Of course you’ll be limiting registration speed massively (which may not be good depending on if you’re in the middle of a Reddit exodus or not), but it is mostly bot-proof. Tildes seems to have pulled it off.