Apparently you can pay to have your website associated with certain keywords. I wonder if AANR or TNS already do this, but I didn't see any advertisements for them just now.
I've also heard of ways where a bunch of people can make websites to take advantage of search engine algorithms and make one website show up much higher in the list.
Getting back to the search engine issue, an interactive search engine might help. For example, when someone types in "nude" or a similar search term, the search engine could ask, "Are you looking for sexual nudity, nudity in art, or information about nudist (naturist) culture and recreation?"

I'm pretty disappointed that internet search still consists of throwing individual words at the search engine and wading through results. There's no way to establish context. Also, I find that search engines more and more are assuming, essentially, that I'm an idiot, and then "correct" what I enter. I search for obscure things, so when I type BCH I really mean BCH, I don't mean beach.
In some ways, I find Wikipedia to be a better search engine than Google. Because then you have people who know things about particular subjects linking to sites which they know are important and relevant. Much better results than having countless computers trying to understand human communication (which is nearly impossible, at least at this time).