Telegram is giving away FREE Premium subscriptions! All they need from you is to use your cell phone as a relay to text out their OTP codes! And the recipient of the OTP sees your phone number! What could POSSIBLY go wrong with this deal?
PLEASE don’t use Telegram! I personally recommend Matrix as it’s totally FOSS, you can self host, there are tons of front end clients to choose from. Or even use Signal. I have my own issues with Signal, the fact they don’t allow third party clients, you can’t self-host, they have a proprietary shim in their stack that only they know what it does, they were pushing crypto, etc, but at least Signal is better than this garbage.
You mean you can try to guess someone’s number before they get an OTP through you in order to be the first to log into their account?
Well then you’ll also going to need their cloud password in order to find anything worth of your effort.
But anyway this is an improbable scenario, considering how vast the user base is, and if we assume telegram implemented some precautions.
Malicious service providers and cloned sim cards pose a much more serious risk if you ask me.