EM radiation and power draw patterns from your device can leak information about what the device is doing. The NSA takes this stuff seriously: https://en.wikip

EM radiation and power draw patterns from your device can leak information about what the device is doing. The NSA takes this stuff seriously: https://en.wikipedia.org/wiki/Tempest_(codename) https://en.wikipedia.org/wiki/Tempest_(codename) There are situations where an attacker doesn't have full physical access to a device but can still observe EM radiation. For example, someone sitting next to you with an EM receiver, observing emissions from your 2FA token.