Broadband users have claimed in a new study that the trend of Wi-Fi hijacking is relatively common.

The study by Moneysupermarket.com found that over four million Brits have used another broadband customer's wireless connection without their knowledge for activities including browsing, emailing, downloading and streaming content.

Such findings are relatively unsurprising when the study also revealed that one in five wireless users do not believe their connections are protected by passwords.

James Parker, Broadband Manager at Moneysupermarket.com, said that hijacking can become a lot more serious if someone is using a connection for criminal activity.

"If people aren't careful, they could unwittingly find a huge bill landing on their doorstep for going over the download cap imposed by their provider," he added.

Broadband provider TalkTalk recently suggested seven million homes are vulnerable to Wi-Fi hijacking and added that the trend is one reason why the government's plans to tackle illegal filesharing through disconnections would not work.