The NSA collects everything it can get their hands on, electronically. This is deemed not to be an illegal (4th amendment) wiretap even when the communication includes an American citizen. To be used in a criminal case against a citizen, a warrant is needed. There are procedures involved for non-criminal cases and non-citizen subjects.

For intelligence uses, the names of US citizens needs to be redacted. The redaction can be undone under certain circumstances, and is called unmasking.

Improper unmasking and leaking of Flynn's communications makes Flynn the victim of a federal felony, one of the few crimes that everyone can agree actually happened.

Spez: For a deeper look, CTH has a good article up. https://theconservativetreehouse.com/2020/05/09/why-is-obama-panicking-now-the-importance-of-understanding-political-surveillance-in-the-era-of-president-obama/

The NSA collects everything it can get their hands on, electronically. This is deemed not to be an illegal (4th amendment) wiretap even when the communication includes an American citizen. To be used in a criminal case against a citizen, a warrant is needed. There are procedures involved for non-criminal cases and non-citizen subjects.

For intelligence uses, the names of US citizens needs to be redacted. The redaction can be undone under certain circumstances, and is called unmasking.

Improper unmasking and leaking of Flynn's communications makes Flynn the victim of a federal felony, one of the few crimes that everyone can agree actually happened.