ConText: A mode of transport for the little ones?  Piggybacking is becoming a very popular sport for the big uns too. Indeed, if you're reading this on the web, someone may be piggybacking on you right now.

But surely I'd feel the extra weight?

With this kind of piggybacking, you may not notice anything at all, although you may find your broadband connection feels a little sluggish. Piggybacking is hacking into someone else's Wi-Fi connection, thus avoiding having to pay broadband charges.

So, next time I'm surfing, someone could hitch a lift without me knowing?

It's also known as freeloading, although pundits are busy trying to think up a buzzier term for it - such as wi-tapping or wi-spy. Up to half of all computer users have sneakily logged onto someone else's connection.

How do they do it?

Easy - your computer automatically lists all available networks. The freeloader can simply log on to an unencrypted network, and no one will be any the wiser. But the practice is illegal - in the UK, being caught piggybacking can earn you a £1,000 fine or up to five years in jail.

But it sounds like digitally looking over someone's shoulder. What's the problem?

They may be looking over your shoulder, but they're probably reading something else entirely. A piggybacker can use your broadband connection to download porn or illegal materials. The material gets traced back to your computer, leaving you with some explaining to do to. Some people also piggyback in order to steal personal details such as credit card numbers and passwords.

How can you tell if someone is piggybacking on your system?

It's not easy to detect - the hacker would have be in the vicinity, within about 50m of your Wi-Fi set-up. If your connection slows from a racehorse's gallop to an old nag's trot, then that could be a sign that someone else has their nose in your trough.

If there's a suspicious character sitting in a car outside your house, then that could also be a dead giveaway. One man was arrested in Cornwall in July after being caught using his laptop on a residential street. So far, though, only 11 people have been arrested for piggybacking.

We're all going to jail!

Computer owners are being urged to make sure their wireless connection is security enabled - most secure connections require a password to log on. Choose a password that isn't easy to figure out. You can also change the settings on your wireless router to allow access to your computer only.

Try at home:

No, son, you can't have a piggyback - get your own wireless connection.

Try at work:

Guys, I think the boss suspects we're piggybacking his network - it took him two hours to download Pamela Anderson.