Leader: 'Quick...stop him... he's going for his iPod!'

Picture these scenarios.

1. You attend a trade show and collect a USB memory stick from somebody roaming the floor handing them out. They're a common freebie now at such events and nobody thinks twice about accepting one. You return to the office and plug it into the USB port with a view to wiping it for your future use.

2. You want to listen to some of your music in work so you plug your iPod in and move across a load of MP3 files onto your desktop PC.

3. You want to take your work home with you and finish off some important documents over the weekend so you drag and drop them onto that wiped USB memory key which you picked up at that trade show.

All three sound reasonably innocuous but somewhere along the line you may have set in motion a series of events that land your company in serious trouble - and if not you, then the next person who does so.

You hopefully wouldn't open an attachment or try to access data sent via email from an unknown source - so why plug a memory key straight into the back of your PC when you can't vouch for its source or its security?

Imagine explaining it over the phone to your IT manager. "I was given it at a show... I don't know by whom... well how was I to know there was a virus on there?"

So there's an element of paranoia in there but that's qualified by the old-fashioned 'better safe than sorry' approach.

Then there is the issue of media files. Can you remember where they all came from? Can you be sure your colleagues are all equally thorough about ensuring they only transport legally 'acquired files? If a company is found to be harbouring materials such as music or movies which are in breach of copyright on their network it will be the company and not the employee who ends up with a fine or a court appearance. And what is to say that if music has been downloaded from a service such as Kazaa there isn't actually some rogue piece of malware in there as well which will be introduced? Removable storage devices are one of the fastest ways to take the firewall out of the equation.

And then there's the practice of taking work home with you. The majority of staff are honest, trustworthy and so hardworking that bosses wouldn't question it but once the practice is established and control surrendered over what data is being taken out of the office the company is opening itself up to all sorts of problems.

However, it only takes one rogue employee - who could now fit most companies' databases onto one mobile storage device - to highlight why this portability of data isn't always a good thing. And then there is the accidental loss. Memory keys can be dropped pretty easily. Can you really vouch for what is on them when they fall from a pocket?

The downside of all of this is that companies must get a lot stricter over the movement of data and a lot cleverer about monitoring and protecting the physical transfer of data.

Some are already taking extreme measures. How extreme? The Ministry of Defence has banned the use of iPods. The US Department of Defense drills out the cameras from mobile phones in some offices. And with each heightened level of concern the reactions from those less well equipped to cope with the diversity of media and technology 'out there' will become more severe.

In truth this issue is already out of hand. What companies now need to do is start recognising the threats and start planning for the best ways to deal with them. Blocking and banning everything will likely cause an 'us and them' culture and actually prove more too problematic to enforce. Meanwhile, doing nothing is no longer an option.