Some of you might have seen Pocket-lint on Sky News discussing a worrying bit of research that the channel has conducted into what happens when you send your laptop into repair shops.

They created a very basic fault with a machine by unseating a RAM chip slightly, and hooked up some surveillance software to see what was taking place in the repair shop. The investigation looked at six different laptop repair places, and all but one misdiagnosed or overcharged for the fault.

One shop called back to say the motherboard was faulty, and it would cost £130 to repair. The surveillance software then recorded the technician looking through private documents and holiday photos. A second technician also looked at the photos, and copied a number of files and passwords onto a memory stick.

Included in the passwords file was online banking details, which were then used to try and log into the bank account. The attempts were unsuccessful, because the details were fake. Staff at the shop - Revival Computers in Hammersmith, West London - deny all knowledge of the hackery.

While this is one isolated case and nothing to get excessively alarmed over as indiciative of the industry as a whole, there are a few tips you can follow to be sure that your data is safe. Firstly, don't store your passwords - particularly your online banking details - in a file on your computer. Just don't do it - it's a massive risk.

Secondly, if you've got private documents, you can encrypt them using software like the paid-for PGP or free Truecrypt. If you do that, make sure that you turn your PC off when you're not using it - if it's left on hibernate then it's possible to get to the password.

You can also store any private files on an external drive, which can then be disconnected and kept before you turn your laptop in, or you can obfuscate files by changing their extension - a text file can be changed to an MP3, then hidden in your music folder, for example.

But the best advice is to rely on your gut feeling about a repair shop. If sending it back to the original manufacturer isn't an option, then try a tech-savvy friend, IT tech at your workplace or a big chain store's IT department. If you're in any doubt, then go elsewhere.