I am sorry for any trouble the imposter "group members" or "supporters" have posted on your friends site. I assure you that all the members of this team do not post on peoples page unless it is to help remove defacing spam. However with dA's new "hide" feature you can hide those harrassing comments so they don't show. Please note [link]
if you have questions, comments or concerns. Again you have my deepest appologies on the harrasment your friend recieved.