Stopped by Police?

You should reliably inform the police that swearing at them is exempt from the provisions of Section 5 of the Public Order Act, as it is a defence that "The defendant had no reason to believe that there was any person within hearing or sight who was likely to be alarmed or distressed by his action."

The CPS, ACPO and higher courts have gone on record to state that a Police constable will may not be likely to be alarmed or distressed by naughty words.

They'll really hate you if you spout that at them.

It's true. In White and Others v. Chief Constable of South Yorkshire and Others, the court held that police officers were men and women of "extraordinary phlegm" and as such, would be "hardened to events which would to ordinary persons cause distress".

Phlegm. What a marvellous word.