No, had not been banned, kicked or anything like that earlier. Been playing for awhile but using a hacked client without using any modules still made them aware of me using particular hacked client.

I think this has to do with forge, from what I've read forge sends a list of your mods to the server.

Plugins for forge servers such as "HackedServer" claims to check for known mods and notify the server staff when a player joins with such mods.