>But if they're getting chat content directly from the phones, say for example by having arranged with the app to cooperate with that exfiltration, then that is

>But if they're getting chat content directly from the phones, say for example by having arranged with the app to cooperate with that exfiltration, then that is, by definition, a back door. Keyword being "if". There's no indication such backdoors exist, as opposed to something like malware being placed, or the phone being physically being tampered with.