Thousands of British homes hooked up to wireless internet connections are leaving themselves open to identity theft and fraud, experts warned today.
An undercover operation revealed that a quarter of all computer users on wireless networks could be hacked into by an ordinary laptop, allowing criminals access to bank account details and other private information.
Cruising the streets in an unmarked van, a team of investigators from moneysupermarket.com toured three cities attempting to force their way into wireless networks to highlight the scale of the problem.
Jason Lloyd, head of broadband at moneysupermarket.com said: "The undercover study showed thousands of internet users had not enabled the security in their wireless modems, leaving hackers free access their home PCs to steal bank details, identity information, or upload illegal content or porn or even finance or execute a scam from someone elses connection."
The amateur hackers tested wireless security on the streets of Liverpool, Manchester and Chester and found they could tap into an alarming 25 per cent of domestic wireless connections.
Mr Lloyd added: "The undercover operation was undertaken to expose the enormity of the problem, with a quarter of the UK population found to be at high risk of personal and business attack by amateur wireless hackers hoping to profit from one of the most common IT security lapses today."
The team went one step further and set up a router and dummy network to demonstrate how easy it was to hack into an unsecured network.
Within a few minutes the team had full control of the network, a personal computer and all its contents.
Jason Lloyd continued: "This is a serious problem which leaves internet users completely exposed.
"Our results found on average one in four of all residential wireless routers are unsecured, meaning anyone can gain access.
"Inviting identity theft or fraud, an unsecured internet connection can become an open door for criminals.
"The repercussions can be severe. Its bad enough your neighbours can use your internet connection freely, but this becomes far more sinister if someone uses your wireless connection for criminal activity.
"This could be accessing your internet connection to download obscene material, gathering personal information to defraud you or even stealing your identity.
"I advise all people with a wireless router to check and secure their connection right now."
Mr Lloyd added: "Whilst we were scanning for unsecured networks we found the scale of the problem appears to be excessive and there were many small business routers which were also unsecured you would have imagined that with potentially many peoples livelihood at stake there would be reasonable measures in place.
"Unsecured residential networks pose one of the biggest IT security threats today.
"Many people are unaware of the security measures that need to be taken to protect themselves from wireless theft."
In a sign that police are taking the problem seriously, two people were arrested at the weekend for illegally using wireless connections in one of the first arrests of its kind.