Millions of households are potentially at risk by unknowingly allowing others to piggyback on their broadband connections for free.
Internet Service Providers now commonly provide with free wireless broadband routers which allow users to connect to the internet from anywhere within a restricted range.
However, research by moneysupermarket.com found out that nearly one in six of all broadband customers surveyed left their Wireless router unprotected and one in nine - that's more than 3.5 million customers says Guardian - said that they did piggyback on someone's else Wireless connection.
Piggybackers use their emails to browse and read emails but also download films and music - which means that the account holders could potentially face huge bills or suspended accounts as they exceed their limits.
Obviously, adding passwords, using the more secure WPA encryption (rather than WEP) and keeping a tab on how much data you are consuming could come useful.
Unprotected broadband users could also risk more trouble if their broadband connections are used for criminal purposes or if their bank accounts are raided.