Only by default, you can opt out this behaviour. But I don't see a problem with it, if someone already has my number he doesn't get much more information (besid

Only by default, you can opt out this behaviour. But I don't see a problem with it, if someone already has my number he doesn't get much more information (beside the fact that I may want to have a "secret" Telegram account. But in that case you can register it with another phone number).