> https://signal.org/bigbrother/ > "When legally forced to provide information to government or law enforcement agencies, we'll disclose the transcripts of that communication here"

Sure, except if there's a nondisclosure provision...

"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. NSLs typically contain a nondisclosure requirement forbidding the recipient of an NSL from disclosing the FBI had requested the information."

https://en.wikipedia.org/wiki/National_security_letter