"S" is for GNU: a Google Alphabet

For some reason, if you Google search on just the letter "s", the top result is the GNU homepage. Hmmmm. I'm sure there's some really interesting insight about Google lurking here, awaiting discovery. My guess is that it has to do with the "s" in the phrase "GNU's Not Unix!" If so, that means apostrophe-s counts as "S" to Google.