Have you noticed that the search engine does not do string searches, i.e exact phrase searches, even though the string is enclosed in "..."? I did a search for "ban-all" and it came up with the correct answers as well as results for "all" and "ban".
I've yet to find (since the demise of AltaVista) a search engine which searches for exactly what you ask it to do, rather than thinking it would be a good idea to be"helpful" by assuming you're an idiot and that it should give you stuff you might have asked for if you weren't an idiot.
Now that takes me back to when I had a dial-up connection and AltaVista was the search engine of choice - until colleagues at work started going on about how marvellous Google was. Tried it, and went straight back to AV.