Just FYI, everything that's done on the site is recorded and stored in our database.  So, by default, we do know who rated who, and we have records dating back to day one.  I also don't know why people get multiple user names and use them to trash others. 

Fortunately, out of the 150,000 unique visitors each month, and the more than 125,000 registered users only one or two people, that we know of, have or are doing this.   So, it's not an epidemic, but it is annoying and certainly an issue for those few who have been attacked in this way. 

Once we uncover and confirm this type of abuse we shut down the infringing party's presence on the site.