Contractors must be especially careful with online passwords, according to one company in the IT security business.

"Unfortunately people often have simple passwords, and they then use the same simple password across multiple accounts. Once you've got that simple password you've got the crown jewels - all their accounts that they're using that for," said Simon Heron, internet security analyst at Redscan.

Several high-profile web and social media sites such as Yahoo!, LinkedIn and Twitter have recently advised users to change passwords following a high impact hack on Gawker Media - a online media company and blog network.

Southampton University student Sara Alotaibi has developed a fingerprint ID system that could work as an alternative to password identification.

It enters passwords for many sites at once by scanning the users fingerprint and according to the Daily Mail, could be available in the next few months for £40.