Methods and corresponding systems in a mobile device for remotely modifying data stored in the mobile device include receiving a message in the mobile device. The message can be a short message service (SMS) message. The message is compared to a secret message, wherein the secret message is a hash value output by a hash function, wherein inputs to the hash function include a text string and a secret text string. The text string can be an e-mail address, and the secret text string can be a password of the mobile device. In response to the message matching the secret message, data stored in memory in the mobile device is modified to prevent unauthorized access. A secret message cancellation can be received in the mobile device to cancel a scheduled memory modification. Memory modification can include erasing data, replacing data, or encrypting data.