Another method that stuck with me: in the early days of bitcoin someone built an "ssh paywall" – i.e. you would pay to enable ssh remote authentication for a mi

Another method that stuck with me: in the early days of bitcoin someone built an "ssh paywall" – i.e. you would pay to enable ssh remote authentication for a minute or two. In essence a hacker would have to pay before attempting to hack the ssh endpoint. Of course the admin would have to pay too but the money would end up on his/her wallet. Quite ingenious if you ask me.