Telegram, a cloud-based messaging platform, stores necessary operational data, including metadata such as IP addresses. In 2024, Telegram updated its privacy policy to comply with law enforcement requests for user data with valid legal documentation, leading to the fulfillment of 900 requests from U.S. authorities affecting 2,253 individuals. The platform has experienced data breaches, including a 2020 incident exposing data from approximately 42 million Iranian users and a 2019 vulnerability that allowed Chinese agencies to identify protestors in Hong Kong.
Telegram features public channels without end-to-end encryption and offers secret chats with end-to-end encryption, limited to the device of origin. Automatic message deletion is available with a minimum interval of one day. While the client applications are open-source, the server-side code is closed-source, requiring user trust in the company to protect data. Metadata collection continues despite end-to-end encryption. Telegram operates on a freemium model, with basic features available for free and a paid tier for additional functionalities. The app is available for download on the Apple App Store and Google Play Store at no charge.