Someone can easily find me in a search outside of this site, as my legal name is on the site and visible. A person had looked me up before after leaving rude messages on a GoFundMe campaign of mine and went as far as to block my personal Facebook account when I had never contacted them and wasn't planning to.
If you feel the cyber bullying or harassment or defamation or privacy invasion rises to a level where your real person has been severely harmed, and you are willing and able to pump a lot of money into chasing down those you feel have wronged you, speak to an attorney in your area for a personal review.
I do not see that what you have described is worth the high cost of pursuing, especially when there is a simple solution (i.e., leave the site). But apparently you are on a mission. Find an attorney who thinks your mission has merit.