How much can you trust unofficial clients for telegram?

Question

Information Security

You can find dozens of clients for telegram on the network. Even on the off site there are links to unofficial clients for linux, windows, etc. How trustworthy are these apps?

Answer 1

What does it mean to trust? You do not know what is happening on the telegram servers, which means that you cannot trust information about the location of the next terrorist attack in the metro. And if you are not planning a terrorist attack, then you can trust everything you want.
Well, and so, obviously, in order to avoid draining messages also from the client, you need to look at their source code and compile it yourself.

Answer 2

They cannot be trusted.

Answer 3

It is strange to trust instant messengers and services that require a phone number for registration. I understand that getting the left SIM card is not a problem, but the format of such registration itself does not fit in with anonymity.