If you decide to -- or are forced to -- cancel your cell phone service, the deactivation only affects the cellular and data connection to the device. The digital contents, like your text messages, contact list and calendar data, are untouched and will still be accessible by any user working with the phone. This is the primary reason many of today's smartphones are equipped with remote wipe capabilities, which allow you to remotely erase the device's data in case it is lost or stolen.

Deactivation Overview

When you deactivate a cell phone, you merely cut off the signal that connects it to the rest of the world. Services that are supported by Wi-Fi will still be active -- including Wi-Fi telephone service like Google Voice and Skype -- and your data-heavy apps will remain functional as long as a wireless network is available. All content that was stored on the device while the service was active will remain on the device until you've properly erased it.

SMS Backup

Although your texts are essentially safe, it's always prudent to back up the messages so you avoid losing everything should the device get lost or stolen. On an iPhone, do this by connecting to and backing up with iTunes -- not iCloud, which maintains email but not SMS. On both Android and BlackBerry phones, a third-party backup app -- Backup to Gmail or SMS Backup & Restore on Android, SMS Backup or txtForward on BlackBerry -- will do the trick. Windows phones feature an SMS cloud backup option, enabled in the main Settings menu.

Remote Wiping

To further protect your personal data after backup, implement a remote wipe feature that locates, rings, locks or erases the device. Though there are third-party apps that do this, you can simply take advantage of the free Web-enabled remote wipe service offered by each mobile platform. On an iPhone, it's called "Find My iPhone" and is accessed on the iCloud Web interface. Android users have remote wipe access using Google's Android Device Manager. Windows Phone users enable the "Wipe Device" option in the Outlook Web app. BlackBerry owners install the BlackBerry Protect app, then initiate remote wiping from the BlackBerry site.

Hard Reset

The remote wipe feature will initiate a hard reset, thus deleting the phone's contents and restoring the device back to its factory settings. While this is an effective method for protecting your personal data, it is not fail-proof. If your phone is accessed before the wipe occurs, the battery dies or there's no signal to receive the command for the remote erase, your data remains at risk. If your phone is lost or stolen, the key is to disable the device as soon as possible and then call your company to report the loss and cancel the service.