Because functionally it's not any different than just trusting the network. If telegram says "trust me, we can't read anything" and signal says the same: the o

Because functionally it's not any different than just trusting the network. If telegram says "trust me, we can't read anything" and signal says the same: the only way you know it to be true is if they have never given you any software that has access to the unencrypted content. OR you only use another network to communicate (and, obviously, you ensure that your clients aren't sending any messages out to anywhere that's not that network). If you play around with the EFF's lovely Tor diagram you can get an idea of what I mean: https://www.eff.org/pages/tor-and-https https://www.eff.org/pages/tor-and-https