Telegram will be able to completely hide your phone number from strangers. Lines with corresponding functions appeared on the messenger development site.
According to the description, users can see each other’s phone numbers only in one case – if their numbers are already in the phone book and they are added to Telegram.
On August 23, Hong Kong Telegram protesters complained of an insufficient level of anonymity in the messenger. According to the director of the Internet society in Hong Kong, Chu Ka-Chong, the police determine the identities of the protesters using the service. Siloviki compose contact lists with thousands of phone numbers. After that, they are added to the groups of protesters and determine the participants according to the list of numbers.
Need help from @telegram. We and multiple teams have independently confirmed a serious vulnerability that causes phone numbers to be leaked to members in public groups, regardless of the privacy setting. Telegram is heavily used in #hkprotest, it put HKers in immediate threats— Chu Ka-cheong (@edwincheese) 23 August 2019
The Telegram development team has stated that they have protection against such methods of deanonymization. They emphasized that the account used to identify the protesters was blocked two seconds after the program started. A total of 85 contacts were imported instead of 10 thousand.
On August 9, Daily Storm talked about the method of determining the phone numbers of users in Telegram. Employees of the “Center for the Study of Legitimacy and Political Protest” said that they created a base where you can determine the phone number and possible name, having only a nickname in Telegram. The developers said that this can be done thanks to one Telegram software vulnerability. The Izvestia journalist confirmed the operation of the system after they found his phone number using a nickname in the database.