Keep in mind, Google doesn't actually go to each site and "decide" which ads it will get. The very same search engines that power Google itself search through the MR site, in an attempt to determine which ads will be the most effective. I'd guess Scientology might be linked to things like "science fiction," which has come up once or twice... not to mention L. Ron's connection through SF books.
I also see ads for cell phone accessories (there's one on my page right now), which would not seem to have a close connection to the site... until you see the mentions of the iPhone, and people reading e-books on PDAs (guilty) and such.
So, there's no reason to bug Google about the ads we see. As was said once by, I believe it was Dr. Richard Daystrom: "It's not my doing, Kirk."