I wouldn't do anything if I knew there was a possibilty to actually cause a confrontation if this person actually decided to come foward if I made him out or if they just decided to come foward and let thereself be known. In your example I would just let the gym manager know there was somebody harassing me and my wife in they gym,an anaonamous member and just wanted to let you know up front in case this person eventually confronts me I do not wish to be in a possible altercation and if they make themself known can you address this behavior with them. It sounds like you may have more of a personal issue with this persons than the wrestlers. I don't know. Like I said I would just notify the principal there is an unknown person in the audiance that has been harassing the wrestlers if this is the case and if thier indentity is found out can they be spoken to about there behavior.
I had a stalker and someone harassing me talking crap that I did not know. They eventually left me alone once I ignored them. There not causing you any physical harm I would just leave it alone. I would not even respond to them any longer if you are doing that now on the message board your talking about. As for that I would hope the board administrator could help resolve the issue.
I work with teens on a daily basis and also deal with this type of suff every now and then with them. What type of role model would I be and teaching them if I was to go and try to track a person down.
Bro, your an adult I can't tell you what to do, just give my 2cents, whatever decision you make, be safe and just remember your actions can influenece others and if there are younger persons involved they may be looking torwards you as a role model.