Special law?
What special law or special treatment is this, then? The relevant law is the Protection from Harassment Act 1997, which prohibits
'a course of conduct-
(a) which amounts to harassment of another, and
(b) which [the defendant] knows or ought to know amounts to harassment of the other.
For the purposes of this section, the person whose course of conduct is in question ought to know that it amounts to harassment of another if a reasonable person in possession of the same information would think the course of conduct amounted to harassment of the other.'
Nothing special about it. It's used all the time to protect people from cranks, bullies and stalkers.