Why communication metadata matters
Metadata is what is written on the envelope rather than inside the letter. It sounds harmless, and it is often the most revealing thing about a conversation.
Steps
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to tick a step and keep a streak. Reading needs no account.
Metadata is data about data.
An email subject line, the time of a call, how often you contact somebody, and where you were when you did.
A pattern tells a story that no message needs to state.
A phone company can see a call to a suicide hotline from one place, emails about HIV testing followed by calls to a doctor, or contact with an abortion clinic.
The law has protected it less.
Police have historically obtained call records more easily than a wiretap, and governments can buy metadata without the hurdles that content requires.
It is hard to hide, because the network needs it.
Something must know where to send your message. Tor and Signal are built to keep that knowledge as small as they can.
So the practice is awareness.
Know what metadata you send, who can reach it, and what it could be used to say about you.