"He leaves his cellphone and laptop at home and instead brings “loaner” devices, which he erases before he leaves the United States 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, “the Chinese are very good at installing key-logging software on your laptop.” 
Traveling Light in a Time of Digital Thievery (NYTimes)