Is it really time to call the police?

Assuming that you aren't getting any help from the board admins/owners through the website,

If I were really concerned about something on another website, I would start by figuring out who owns the website by typing the name into the following link.

https://secure.registerapi.com/services/whois.php?siteid=4798

I would attempt to contact the site owners listed here to seek assistance.

If I was still concerned, after speaking with the site's owner or agent,

Then I would contact the authorities in the jurisidiction where the website's business or owner is registered and then follow leemann's advice.