If an Android device (phone or tablet) has ever logged on to a particular Wi-Fi network, then Google probably knows the Wi-Fi password. Considering how many Android devices there are, it is likely that Google can access most Wi-Fi passwords worldwide.
Recently IDC reported that 187 million Android phones were shipped in the second quarter of this year. That multiplies out to 748 million phones in 2013, a figure that does not include Android tablets.
Many (probably most) of these Android phones and tablets are phoning home to Google, backing up Wi-Fi passwords along with other assorted settings. And, although they have never said so directly, it is obvious that Google can read the passwords.
Sounds like a James Bond movie.
Android devices have defaulted to coughing up Wi-Fi passwords since version 2.2. And, since the feature is presented as a good thing, most people wouldn’t change it. I suspect that many Android users have never even seen the configuration option controlling this. After all, there are dozens and dozens of system settings to configure.
And, anyone who does run across the setting can not hope to understand the privacy implication. I certainly did not.
In Android 2.3.4, go to Settings, then Privacy. On an HTC device, the option that gives Google your Wi-Fi password is “Back up my settings”. On a Samsung device, the option is called “Back up my data”. The only description is “Back up current settings and application data”. No mention is made of Wi-Fi passwords.
In Android 4.2, go to Settings, then “Backup and reset”. The option is called “Back up my data”. The description says “Back up application data, Wi-Fi passwords, and other settings to Google servers”.
Needless to say “settings” and “application data” are vague terms. A longer explanation of this backup feature in Android 2.3.4 can be found in the Users Guide on page 374:
For details and more information click the source link below.