Individuals have to change privacy settings to disable calls from strangers. As for blocking DM by other group members, it's something which Telegram doesn't (want to?) implement.
How to protect your self against spam chat: ❗️ Read Me So You Can Keep Safe❗️ 📌 Please do the following in your Telegram app 📱 1️⃣ Go to: Settings 2️⃣ Select: Privacy and Security -> Groups 3️⃣ Select: Who can add me to group chats? -> My Contacts 🔓 This will protect you from scammers adding you to FAKE groups/chats 🔓 1️⃣ Go to: Settings 2️⃣ Privacy And Security 3️⃣ Phone Number : Nobody 4️⃣ Forwarded Message : Nobody 5️⃣ CALLS : Nobody Thank you. Stay #SAFU.
Обсуждают сегодня