That's the problem being decentralised setups. We are talking about setting up rules to control when the scope itself is not defined.

It becomes the responsibility of the service provider (in this case steemit) to have monitor and regulate flow of contents.. which can be done by building countermeasures or hiring a top class system dedicated only for this purpose. Like you said it need sto take down the content Which are flagged till the creators provides justification. Same goes for the very unfortunate second case.

All i wanns say is freedom too can be really ugly sometimes.

Another solution is use this decentralised system against such thing.