Hi Ehren,
like Marie said:
there might also be a good chance that those people who are complaining about your site just simply throw their links around the Internet where ever they can...and THATs the reason why they get penatilzed.
And now the panic-mode has been engaged and I am sure you are not the only one who gets Emails from them 
Either strip the URLs from the user comments via regexp-function or no-follow them
So I was wondering: are there any other countries where such contests are being held? I have not heard of any examples and I am quite curious if any other SEO communites out there have something similar going on