Okay! I think I have an answer for you. I found this:
http://webcache.googleusercontent.com/search?q=cache:WdHknYu...
This is an HTML page on a WordPress site. A hacked WordPress site. It's SEO spam and is rather successful. It's not a proper page and so has no title, but has all the keywords for a search and a bunch of links at the bottom that it's trying to rank higher for whatever search.
This isn't Google's fault necessarily but rather there are compromised WordPress sites out there that look fine to the owner, but when the referrer is Google, or the user-agent is the google bot, the website produces different results than if a human is viewing it.
About a year and a half ago almost half the results I was getting consisted of those. Most of them were on `.it` TLDs, and I've been blocking all those results since.
There is an official Google publication on this phenomenon that was published a really long time ago, but I'm unable to find it anywhere. Would anyone reading this perhaps know where to find it?
This is interesting. Just the other day I did a search on DDG and had the same thing happen, a full page of .it TLDs that vaguely matched what I was searching for. This is the only time I have seen that and unfortunately I don't remember what search terms I used, probably something related to my recent video card issues.