Practical jokes have been with us ever since the first Stone Age man decided it would be a bit of a jape to hide a sabre-toothed tiger's tooth under the pelt his mate was about to sit on.

However, what our prehistoric ancestors didn't have to hand were mobile phones to record their antics and websites such as YouTube that enabled them to share the joke with the rest of humanity.

As the students of Worcester College of Technology have proved, practical jokes have gone hi-tech.

Not only did the students acquire a device to jam the radio signals of car owners' key fobs, but they filmed the general confusion as drivers tried and failed to lock their vehicles' doors, and then they posted the resulting clips on the internet.

In this case, the joke was relatively harmless, and will no doubt cause much mild amusement among those who view the clip on YouTube.

There was little malicious intent, and any embarrassment suffered by the victims would have been fairly low. Many will also admire the students' ingenuity in coming up with the idea in the first place.

But as the recent happy slapping' craze has shown, not everything filmed for the amusement of others is so harmless.

The opportunity to share the joke with thousands, and even millions, of people has provided the incentive to create ever more elaborate and cruel pranks, and vicious assaults have even been carried out for the benefit of the mobile phone lens.

Worcester's students have had their laugh with the key fob prank. Let's hope they leave it at that.