I know some people who are very particular about it; it's OK for me or another LEO to call them a cop, but not for the public. It's also a complement in many cases; if some cops call someone "COP", it means I think there more than a simple guy with a badge who happens to be a police officer -- they're transcended the minimum standards to be good.Oh for the love of pete!!! Do you like to be called that or not?!
By the definition in that article something like the following would make sense: My friend was once copped by a copper who was copping several others at the time.
Personally... I don't care. Cop, Officer, LEO... all beat pig and many other names that won't pass the profanity filter.
I just also will debunk the false origins of the term; bad info doesn't help anyone.