Intimidation.
Anyone running even a small data center knows that the US government can just walk in the front door and seize whatever they want. Yes, there is the formality of a warrant, but most judges will sign off on anything related to terrorism. (No judge wants to be 'that guy' who didn't help the police catch the Pitt bomber before he kills a bunch of people, etc etc.)
This gives them the ability to intimidate other ISP's & data centers. "Oh, you don't want to cooperate? OK, we'll be back with a warrant. How much are each of those servers to replace? What about that nice SAN over there? Those 10GB switches? Yes, you'll get everything back when we're done. Might be a few years though...."
Yes, it's a game. Yes, its nefarious. But, it works.
Is it ethical? Probably not. Is calling in 100 bomb threats ethical? No.
Do two lefts make a right? No, but three do.