Turf was created when the NSA added divisions to collect telephone metadata. As people were moved and employees were added, interests were created in maintaining a self-perpetuating system that has no purpose other than to sustain itself. As a rule, bureaucrats defend their turf.
The NSA program has not stopped terrorist attacks. But the President's address on it today didn't threaten its existence. Turf has been created. We'd be better off addressing the cultures and incentives that create it than making more of it.