A police unit parked outside a guy’s house and confirmed it was him in the real time chatroom, by cutting his internet and seeing him drop off.
If you want real anonymity on the Internet, never use push notifications. Always “pick up your mail” periodically from random endpoints on the Web.
You can accumulate encrypted messages at random urls instead
Note that a similar thing happens with any two-way conversation; if an immediate reply is expected and there's no reply, it's not a conversation anymore. (For more possible reasons, though.)
Disappearances can't have good error messages if you want plausible deniability. This will make any UI much less user-friendly.
Have many servers who just accumulate encrypted packets and then only the host knows how to reassemble them in order and decrypt.
Could probably be somewhat realtime if executed correctly.
*You send PGP encrypted messages via Mixmaster Remailers (via Tor) and preferably use a hashed subject (hsub) so that the intended receiver(s) can filter out their messages.
https://lists.gnupg.org/pipermail/gnupg-users/2019-March/061...
I guess I'm going off of too few details probably, but this doesn't seem like a very sound strategy to me. It's certainly not impossible that the real criminal lost internet around the same time as some suspect's was cut by the police. I know I've shown up as online to other people for up to several minutes after losing internet in real-time situations (e.g. games). I suppose police just need "reasonably likely" to take action though, not definite reasons.