Before big companies started to host the gaming servers, it was easy to get the other users IP address and do a bit of tracking. But, now, they would only get as far as your ISP, not down to your level, so you are safe.
Also, anyone can say that they are good and not know a thing. It is those that do not say anything that are the ones that know what they are doing. So, if you have someone running their mouth on how big and bad they are in hacking you, relax, but, as a precaution, it is smart that you did delete your clan. Just go back in, change your user name and such and start over again. More than likely, if it is a popular game, you will be put on another gaming server and never have to deal with them again.