I think it should be a suspendable/bannable offense to threaten people with GM action for non-prohibited conduct (whether by pretending to be a GM or by insinuating a ban is forthcoming for reports made about the person).
There are some angry people in chat that feel the need to threaten others when chat isn't exactly how they'd like it, and I don't think it's acceptable to invoke the power of the GMs to push your own crusade against people who disagree.
Just my thoughts.
Best,
LC