Let's say that I notice a really inappropriate message in chat from a 10k+ (this will usually mean that they have been hacked or something - not that I'm asking about a real situation that has occurred, but just about a hypothetical one), if I were to flag it up, would they be able to see that someone had flagged up their message if not who? And is it the same with moderators?
Even moderators are not notified that a flag has been raised on their own message.
Moderators (but not 10k users) can see a history of flagged message for any user including themselves. This log does not include the identity of the flagger.