The Attorney General in England is to take legal action against users of social networking sites who published photographs purportedly of one of the killers of Jamie Bulger.
There is an injunction banning identification of either of the guilty parties.
A spokesman also points out that even if the images are not actually the men concerned, the fact that they claim to be (and thus potentially put innocent lives at risk) is still regarded as a breach of the injunction.
The law of contempt is tricky and complex – as is the law regarding libel and incitement.
Lawyers spend years studying before they qualify.
Media workers also study those areas of law relevant to their business.
Despite what people may think there are endless checks made in-house on everything that is printed or broadcast by the mainstream media.
But as we know from reports about what's been appearing on social networking sites regarding recent trouble here (sites on both Twitter and Facebook) there are people out there who do not have the first notion about what is legal and what is actionable.
Or about the sort of trouble that they are walking themselves into.
Here too, posters are due to find themselves facing action over defamatory and incendiary material they've spouted online.
Who should the authorities focus on though?
The social networking giants? Or the administrators of those sites hosting the bile?
Whinging that they didn't know that something posted on your Facebook page was breaking the law isn't actually a defence.
If you're going to play big boys' games, you need to learn the rules.