Letters can be intercepted, letters have tracking, letters of this magnitude will require certification, and at the very least will require a courier. All of th

Letters can be intercepted, letters have tracking, letters of this magnitude will require certification, and at the very least will require a courier. All of that assumes the letter can be delivered, and also assumes that the recipient believes that the letter is authentic. If I sent you an authentic looking NSA letter, would you just do what you're told? Fat chance... An email/phone call to a legal department is much less work and provides all the same protections.