Damage Control. Shades of Bud Light; but a better attempt to side with the customer compared to Bud Light.
As an example of why it "Waffles" on their adhering to US Constitutional Principles:
A national security letter is an administrative subpoena issued by the United States government to gather information for national security purposes. NSLs do not require prior approval from a judge.
Just a reminder of what the 4th Amendment says on the subject:
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.