I think you mean GAF (reversed spelling). What is Netflix going to give the NSA? Looks like Osama bin Laden loves House of Cards. What about Amazon? The terrorists use AWS and ordered a bunch of pressure cookers?
“Amazon” — the company with massive contracts with the CIA and DoD, full time Alexa microphone in millions of homes, owner of Ring video doorbell, runs something like half the internet through their servers. Yeah I think they might have something the control freak “intelligence community” would be interest in.
IME you are served a subpoena to testify to specific information that they think you have, and if you can provide it prior to the date of testimony, you don't have to show up.
Suspect a warrant would be if they wanted to take something in your control, but I've never been subject of that kind of thing.
A cellphone would give information about the cellphone. Might be single use/shared burners - might be turned off. In certain cases the Netflix account might give better information (For example, imagine Snowden login in to Netflix in his hotel room. Or more likely, one of the journalists logging in to theirs...).
You might have a point regarding Netflix but Amazon’s cloud computing business is bigger than its online shop and used extensively the world over and has a lot of SaaS products based on communications alone (never mind all the other stuff in their portfolio)