Telegram messaging service might get blocked in Russia
It appears that Telegram will not provide FSB with any keys and will therefore be blocked in Russia. There is an established procedure for blocking messaging services which was already tested on other services (such as Line and Zello). However, the question remains how blocking will be technically done.
Theoretically, the authorities can block specific IP addresses of Telegram which can be problematic if Telegram uses a lot of IP addresses and is able to change them quickly. Some technical specialists claim this is how Zello currently bypasses the blocking, i.e. by frequently changing their IP address. However, even if Telegram took this approach, it would still decrease the number of users, since frequent unavailability of the service would be inconvenient for most of the users.
The second option could be DPI (deep packet inspection) equipment which would search for Telegram in online traffic and decrease its capacity. However, such an option has never been tested in practice by Russian telecom operators, and according to their representatives the operators are not technically prepared to do so.