didn't they comply with Indian police request and handed over complete user data and ip logs to them?
IPs are a bit tricky to handle though, because they're required to be stored for session management since Telegram is cross-platform and has independent multi-device login.
This low-tech "attack" would also work even better with WhatsApp and Signal (better because in Telegram secret chats don't get shared between multiple devices while in WhatsApp and Signal they obviously are - cause every chat is encrypted).