Yes, this has been a pretty disturbing trend, and it has chilling effects.
For example, the old Section 28, and its prohibition against "promoting homosexuality" was pretty vague, and had lots of knock on effects, because no one much fancied being a test case. At one stage, the council owned bus company in Edinburgh was unwilling to accept adverts from the local gay switchboard, because that might be promoting - though in fact, the actual paragraph was pretty clear that it referred to maintained schools, that chill spread far and wide.
Then there was the Criminal Justice Act 1994, which bravely tried to define what a rave might be and even offered up a legal definition of music:
"“music” includes sounds wholly or predominantly characterised by the emission of a succession of repetitive beats."
The noble tradition didn't start there, of course; obscene publications with it's "likely to deprave or corrupt" is a bit woolly, and governments of all colours have enjoyed passing poorly worded legislation in recent years.
This has been a charming month on the legal front really - not only have the police decided that just watching something might make you a terrorist, thereby leaving us all in mortal fear of auto-play video, but the appearance in court earlier this month of two people who had old material they'd not deleted from their phones potentially leaves us all at risk from an unsolicited MMS or Vine as well.