"If you haven't been sending money to the middle east, they weren't looking at your bank details."
What's your source for this? And how would they know this before looking?
According to even the New York Times report, they were looking for specific transactions by specific people/organizations.
It was not a "give us all your records and we'll sift through them for something that might be of interest -- particularly Canard's checks to the butcher" kind of operation.
Let's say you send some money to a known terror organization & no, the transactions are not limited to those in the ME. They know you've sent money to the terrorist account, because they have a lawful warrant to look at that account. They take a peek at your account to see if you're sending money to any other known terrorist account or if you are receiving money from one. If you're not, there's no reason to look at your account further. If you have, they take out a secret warrant for all of your transactions. Everyone sending you money or receiving money from you then gets a peek.
If all of these transactions require a warrant, set up the full time court to take care of the flurry of paperwork. Your rights would be better protected that way, though there would a more lag time & more opportunity for bad actors to pull off their plans, before they get caught.