He leaves his cellphone and laptop at home and instead brings "loaner" devices, which he erases before he leaves the US and wipes clean the minute he returns . In China, he disables Bluetooth and Wi-Fi , never lets his phone out of his sight and, in meetings, not only turns off his phone but also removes the battery , for fear his microphone could be turned on remotely. He connects to the Internet only through an encrypted, password-protected channel, and copies and pastes his password from a USB thumb drive. He never types in a password directly, because, he said, "Chinese are very good at installing key-logging software on your laptop." - Travel precautions in the age of digital espionage.