I ignore also some group on telegram that keep adding me to unknown group, I just leave immediately when I'm not familiar with such token. Just for my account safety too.
Good call. On a related note, anytime somebody is asking for something that feels...odd - it probably is. I know that some fork coins have really worked out for small sets of people, but if you have to give your private key to claim them, think very very carefully. If somebody is saying that you need to give anything that is unusual from the majority of forks/airdrops/etc. do a check with others here or in other respected forums to understand the risk. Leaving unknown or auto-added groups is definitely smart.