Two in five Wi-Fi users (40 percent) don't know how to change the security settings on their home network, according to the Information Commissioner's Office (ICO).
More worringly, research commissioned by the ICO and conducted by YouGov also revealed that 16 percent of Brits with a home Wi-Fi network are running it unsecured - either because they don't know how to secure it, or because they simply have no qualms about it.
In a bid to ensure Brits with home Wi-Fi networks step up their security, the ICO has published some advice on how web users can check the security settings on their Wi-Fi router along with information on making the networks more secure, including creating strong passwords and making sure the information sent over the device is encrypted.
The ICO is also calling for ISPs, retailers and manufacturers to make sure Wi-Fi equipment is issued with clear advice explaining the risks of using an unsecured connection.
"People wouldn't go out and leave their front door unlocked, but many are still surfing the internet without adequate protection for their personal information," said Steve Wood, head of policy at the ICO.
"Leaving your Wi-Fi connection unsecured allows people easy access to your network. This increase in traffic could reduce the speed of your connection or cause you to exceed a data cap imposed by the service provider. Even more worryingly, however, it also leaves you open to the actions of rogue individuals who may be using your Wi-Fi to carry out potentially criminal actions without your knowledge."
Chris Davies, general manager of D-Link UK & Ireland, said securing wireless networks is paramount, but the ICO research shows people are still falling short.
"There is no doubt that in the past setting up security on wireless networks could be tricky, but this is no longer the case with most wireless products. Security can be set up in a couple of minutes using set-up wizards, with no prior technical knowledge required," he said.
"We welcome the ICO's guidance in further highlighting the importance of protecting yourself against the dangers of cyber crime and identity theft."
See also: Wi-Fi is 30% slower than fixed broadband