I'm not sure if "allow" is the right word here. Really the NSA can set up another Room 641A at any company they want regardless of that company's wishes and wit

I'm not sure if "allow" is the right word here. Really the NSA can set up another Room 641A at any company they want regardless of that company's wishes and with a national security letter the company can be prevented from even telling anyone (like their customers or the media) about it. I was furious when Obama granted telecom companies immunity from prosecution for their role in the warrantless spying, but really it's not exactly fair to pushing people who are strong-armed into compliance.