You kick the problem over to your (trained) ombudsman.
I have had some experience with ICANN's trained ombudsman. To put it
mildly, he was not part of the solution.
While I certainly agree that harassment is bad, in the IETF where
nobody is in charge and authority, such as it is, flows from the
bottom up, it is surprisingly hard to create definitions that capture
the behavior we want to stop, without also enabling endless whining
and nitpickery by people with what I might call an outsized sense of
entitlement and a lot of free time.
This isn't saying to give up, but it is saying to think carefully
about the scenarios, particularly ones involving people with no
interest in playing fair.
R's,
John