It's not our fault, Hidari.
We agree to have Google ads, so as to pay for the forum costs. They choose which advertisements to post. Actually, some of them would not be our choice at all. In the past I've seen one advertising foreign women available for marriage, any number for ebook sites and gadgets, some for programs that we aren't terribly enthusiastic about, and the Scientology one that you mention.
Clearly, Google Ads has profiled this site as being full of geeky single men.