Well, they’re not armed and don’t have general policing powers, so one can get away with being pretty crude to them so long as no physical violence is used.
I’ve used unprintable invective against the driver of a van full of “NYPD Traffic” people (aka meter maids), which cut me off while cycling. Legally or physically, they couldn’t do a damn thing about it.
I actually regret it a bit, but I didn’t at the time since the driver came close to causing me to hit the van.
