In this photo illustration an Amazon logo is displayed on a smartphone with stock market percentages in the background.

Wickr Me, an Amazon-owned encrypted chat platform, stopped accepting new users after Dec. 31 and will shut down completely on Dec. 31 of this year, according to an announcement from the company.

The decision, first announced in November, follows several controversies surrounding the ultra-secure chat app, which allowed users to sign up without a phone number or other potentially identifying information, making it a favorite for security-minded groups including hackers, drug dealers and journalists.