From the article:
The Federal Bureau of Investigation is trying to unmask the operator of Archive.is, also known as Archive.today, a website that saves snapshots of webpages and is commonly used to bypass news paywalls.
The FBI sent a subpoena to domain registrar Tucows, seeking “subscriber information on [the] customer behind archive.today” in connection with “a federal criminal investigation being conducted by the FBI.” The subpoena tells Tucows that “your company is required to furnish this information.”
The subpoena is supposed to be secret, but the Archive.today X account posted the document on October 30, the same day the subpoena was issued. The X post contained a link to the PDF and the word “canary.”