Spear phishing wears a source's name

The mail looks like a leak: a spreadsheet, a recording, a legal PDF. It may use your beat, a recent byline, or a name you recognise. That is not a reason to open it on the laptop that also holds your source list.

This is not a lesson in hiding from lawful process. It is the CPJ starting point: think what happens if the device or account is taken, then slow the file down.