[tsimionescu]

Excellent points. Platforms obviously need to have some power of moderation for spam and off-topic remarks.

One idea for a type of system for adjudicating disputes would be something similar ot the jury system used in common law countries. When a conflict arises (some moderator deletes a post whose poster feels is within the rules), a set of users could be chosen randomly and asked to deliberate whether that is the case or not. This would be similar to a court proceeding, with the accuser and accused allowed to argue their case, but much less formal. Participation in such juries would just be a cost of using the platform. This would not apply to posts that are removed for legal reasons, where the regular legal system would have to be used instead.

Note that spam is generally already illegal, and advertising products with specific health claims that you do not have proof for is definitely illegal in many jurisdictions (fraud / false advertising).

I would also expect that any such moderation should only apply to broadcast messages. Direct, private communication between two or more people must not be moderated in any way (though users should be given certain tools to help them, such as optional spam filters, the ability to block specific people from sending them messages, etc).