I would assume not the people who openly said they're spying on them.

Sure, but it's not a crazy assumption that this government agency uses an encryption that the NSA can't just walk past, especially considering they definitely know the NSA will try to look in on it.

Yeah, I know when I'm transferring billions of dollars in vulnerable digital assets I always make sure to recite all relevant facts over an unsecured phone call, while using an unsecured web connection to do the transfer.