For what reason would an ISP need to distribute a warrant canary?

“Daylight is supposed to be the best of disinfectants.” – Justice Louis D. Brandeis.

We are in a period of uncommon open discussion over the service’s forces to subtly acquire data about individuals. The disclosures about the monstrous NSA mass observation program have brought up difficult issues about whether these forces are fundamental, legitimate, and established. Mystery observation abuses not just the security interests of the record holder, yet the discourse interests of ISPs who wish to partake in these open discussions.