I assume that when the FBI sends a request to a tech company about a user, they probably also contact lots of other tech companies too about the same user... Which raises the question: Where is the Google notification about the FBI request... How about the Facebook notification? The VK or OK notification? How about the Twitter notification? Did these tech companies hand over data without notice, even though the order…
You assume a lot. I know it’s fun to pontificate about dragnet surveillance, but in general when issuing / granting a warrant there has to be some kind of specific target and scope. In this case it’s likely the FBI knew the Sci-Hub founder was using iCloud email and so they could get a warrant for that specific account for a specific time range.