You couldn’t be more wrong.
The feds absolutely trawl everyone’s communications .
Part of how they do it is to go after a target and request Whole Pipe access to a service providers network.
They have no client to protect and they do not minimize the information collected and stored.
IOW, They do not discard information that is not relevant to the request.
I gave a huge dissertation on the great Laz’s thread Saturday.
I think I saw it, but I might be mistaken; got a link to it?