The study, which took in responses from 120 internet users on both sides of the Atlantic, asked them how they protected their privacy online, including their use of encryption, and how they protect their data in transit via email or USB stick.

Almost a third (32 per cent) of those questioned admitted that they had lost a USB key in the past.

Of these, only 14 per cent said they had encrypted the contents of stick and nearly three quarters (71 per cent) had left their data unprotected from the eyes of others.

Curiously, 15 per cent of survey respondents admitted they not know if their data was protected or not.

Despite these startling statistics, just under half of those questioned (47 per cent) said their USB-stored data was adequate. 28 per cent, meanwhile, thought they did not use adequate protection.

When asked if they had encryption software installed on their computer, just over a fifth (22 per cent) admitted they were "unsure" or "didn't know" if they did, despite the alarming trend of increased identity theft, phishing attacks, and other online risks that drives the need for users to adopt encryption.

Commenting on the survey results, Michael Marzy, Steganos' managing director, said that people would not leave their diary or wallet open for anyone to see in a public place, and yet they do not seem to take the same care when online.

"We all store so much confidential data on portable devices such as laptops, notebooks and PDAs," he said.

"The increasing risk of theft means that everyone, be it a home computer user or business user, needs to take responsibility for protecting data, both by encrypting current files and shredding those that are no longer needed," he added.