I'm surprised nobody (that I've seen) has discussed timelocked coins for identity establishment. It's cheap for honest actors and expensive for spammers (since as soon as their identity is identified as spam it's toast and they'd need to lock up more coins to create a new one)

I think there may need to be some standardization on POW delegation for this to work, as alluded to in the POW NIP for it to not lock mobile users out. Even likes get POW'ed, which I accidentally discovered while I had my POW set to 40. I had to kill the client process, it pegged my CPU