[Snoozus]

I find this wording also "a bit strange".

It is not a mathematical impossibility in any way.

For example they might be able to read the backups, the keys might be somehow (accidentaly or not) leaked...

And then the part about Telegram not having end2end encryption? What's this all about?

[FabHK]

Telegram defaults to not e2ee; you have to initiate a "secret" chat to get e2ee.