An active but unused Wi-Fi connection on a smartphones or tablet can be an invitation to hackers. Wi-Fi and Bluetooth should both be turned off when they're not immediately needed, advises the TUV, an agency that rates consumer products in Germany. With active Wi-Fi there's the risk that the device will automatically connect to an unsecured network. And if one then uses an email app to connect with the mail server and transmits the account's username and password it's possible for an attacker to capture this sensitive information.
Hackers might not only be able to get information about the email account but by using the "Forgotten password" feature could gain access to other accounts and services that use that email address, the experts warn.