Edward Snowden famously covered himself and his laptop with a blanket in his Hong Kong hotel room to prevent hidden cameras from capturing his passwords.

The NSA bulk metadata program collected routing information, time, and duration of phone calls, rather than recording the actual audio content of the conversations.

Snowden required visitors to place their smartphones inside a mini-fridge to act as a makeshift Faraday cage, blocking outgoing radio and audio signals.

The PRISM program involved the NSA collecting direct internet communications, such as emails and messages, directly from the servers of major US technology companies.