I have seen some new frauds recently on the telegram. They chose telegram as the medium for scamming. They stay in some active groups and find the target. They also once targeted me. They gave me the various link by personal message. And after clicking on the link the link told me to create an account. And if I want to do create an account they will want the wallet's private key. So I think they are a Very terrible scammer. We should be safe from them. Otherwise, we will lose all our cryptocurrency. They send me so many messages that I stopped using telegram for them. Besides, there are many scam bots in the telegram. Those bots never give payment. So I think it's not safe to earn in the telegram. It is best to use it as a communication medium.
Thats why i never entertain Personal Messages on Telegram unless i know the person,but even if still I don’t open links provided by others as i know most hackers use links to get inside your systems
Since the existence of various ICO projects, telegram has become one of the communication media of these projects and even the ICO project has provided telegram campaign services. So it's no wonder there are so many fraudsters organized on telegrams. I agree that telegram is better used only for communication than used for various paid campaigns.
But what OPs telling us is the group itself and not the telegram campaigns ,the other members contacted them ,and i had some experiences like this but never entertained even a singke one