Support for adding moderation services like this. You could have a dedicated list for these, and have actions configured based off of the type of flag. (blur media, mark as spam/hide, ignore)
There can be services dedicated to scanning content and aggregating reports
I think a relay based model may work better.
MOD-REQ
This skips the overhead of signatures for each moderated event, and moderation may not be instant (so servers can wait a bit before responding).
And you can for example blur media or hide events while within the timeout.
Types of flags are specified in NIP-11.
