Backbytes: Someone sent you some unsolicited smut? You may be prosecuted for it

How to get someone you don't like into trouble: just send them some filth and call the police

If you're ever "in trouble with the law", regardless of how trivial the alleged offence, these days you can invariably expect to have your PC, phone and any other computer sequestered and searched as a matter of routine - no warrant required.

And don't even think of explaining yourself to the police. After all, anything you say "can and will be used in evidence against you" - well, they do have performance targets to chase.

Even so, the sentences handed down to Gary Ticehurst and Mark Kelly are astonishing. Not for their possession of what were described in court as "truly disgusting" images and videos on their phone, but for the fact that they were sent completely unsolicited from an unknown source via WhatsApp.

Ticehurst and Kelly, who had to defend themselves in court, were sentenced on one count each of "possessing an extreme pornographic image likely to cause injury", and two and three counts respectively of "possessing pornographic images involving animals".

Kelly claims to have deleted the material from WhatsApp, but didn't know that the images had been saved on the "camera roll" feature of his Android smartphone. "I didn't even watch the full content of the video. It was very sick and disturbing," he told the court. Ticehurst, meanwhile, had simply forgotten about the files.

The police found them, though, on their phone after stopping the pair over other matters.

"It makes a big difference if someone goes out of their way to seek it, or if they're sent it by some mischievous colleague," said Judge Worsley, summing up.

Astonishingly, instead of dismissing the case, the judge decided to hand them both a two-year conditional discharge and relieve them of £500 each. But, hey, that's what "strict liability" means in UK law - effectively reversing the burden of proof.

Corrupt policemen will no doubt note that they don't even need to fit people up any more - they can simply spend the evening sending filth to their targets' email or social media accounts from anonymous accounts, and swoop the next morning.