I've had a bunch of bots doing oddly specific nonsense searches in my search engine, stuff like casinos, online pharmacies, warez. The bermuda triangle of dodgy internet sites. They are very strange because they are both generic and specific at the same time.
Here is an example:
> skyrim english voice files (and subtitles) latest version
You get no results with my search engine, but interestingly, if you feed that into google, you get some pretty dodgy top results.
It looks like the type of SEO spam nonsense you find on websites, hacked wordpress deployments are often rife with these types of keywords. I think they are trying to manipulate a would-be suggestion algorithm somehow. Problem is I don't do anything with the user input.