[foldr]

Come to think of it, does the First Amendment actually stop the police in the US doing the same thing? The article reports that the police acknowledged that no crime had been committed. I don't think that there's anything unconstitutional about a police officer calling someone up and asking them questions.

[Kalium]

In the US, a pattern of police doing so could be actionable.

It would be rather difficult for most American PDs to justify devoting resources to investigating somoene being mean online unless it was in a fairly narrow set of categories (clear and specific threat, harassment, etc.).

[foldr]

What's your basis for saying that it could be actiobable under the first ammendment?

It would be equally difficult for British PDs as far as I can see. But police in both countries don't always use resources wisely.