Over the past decade, webcams have become ubiquitous and we've gotten used to the occasional skype or other video call. And there communications go, the spooks follow ...

There's nothing terribly new about the Picturephone ; video telephony goes back to the 1960s, and was a very long time catching on. I myself remember one excruciating intercontinental video conference from 1994. (The problem with using it for work is that you can't look away from the camera, relax, or otherwise show any sign of weakness or humanity. And it doesn't get you much extra, over a regular phone call. But I digress.)

It turns out that the British equivalent of the NSA, GCHQ, has been spying on Yahoo webcam users. And they're a bit upset by what their Optic Nerve program revealed.

For starters, it turns out that 3-11% of Yahoo! webcam traffic involves "undesirable nudity". Which presumably means the users are not merely baring their faces at the cameras, but baring their other bits, with rather more enthusiasm than Big Brother's salaried employees are happy about. It's nice to have a figure for just how much of the internet is for porn; more amusingly, the serious people at GCHQ seem to have been taken aback to discover that people on Yahoo! were actually broadcasting their amateur action for all and sundry to see.

The deeply serious spooks tried to spare the sensibilities of their employees by employing automatic image porn filters. Unfortunately naive porn filters block images on the basis of how much of the picture consists of flesh tones. In the case of video conference calls, this turns out to be too much: they were getting lots of false positives (images classified as pornographic that were not in fact so), and as the whole point of the program was to trial face recognition software in order to detect Bad People Discussing Terrorism On The Internet, this was a bit of a problem.

More hilariously, GCHQ is not a law enforcement agency but part of the defense establishment, and the UK has one of the most draconian child pornography laws in the developed world. Possession of child pornography images is a strict liability offence — intent has no bearing. Only a handful of categories of people are permitted to possess this material: police investigating a crime, some forensics specialists, lawyers and judges and other people involved in a trial. GCHQ personnel stumbling across images of child abuse could be committing a criminal offence. And possession or dissemination of indecent material (pornographic but not criminal stuff) on government computers? Oh dear, the mind boggles.