This seemingly innocuous phrase is the semi-secret passcode for identifying people from the Something Awful Forums. Forum-goers, who call themselves goons, are a fairly tight-knit group, and if two people in real life who have never met before are both "goons", then they already have a sort of odd solidarity with each other, just by virtue of being goons.
Thus, the usefulness of this catchphrase. The origin of it is from an ICQ prank that Lowtax, owner of Something Awful, pulled on some poor unsuspecting fool. The prank involved evil pusher robots pushing grandma down the stairs. Lowtax proceeded to further frighten the victim by having the robot ask "Do you have stairs in your house?", implying that he (the victim) would be pushed too. I know this prank sounds rather inane. If you're curious about it, just go to Something Awful and read it, it speaks for itself more than I could explain it.
In any case, every forum goon from SA will recognize this. They just will. If you go to the forums, you'll see that there are a ton of phrases like this that goons will recognize, but this one is the best for covert goon identification, since it seems so innocent. If you just go up to someone on the street and say "Do you have stairs in your house?" to them, they will most likely stare at you in puzzlement, and no ill effects will ensue.
But... if the target is a goon, on the other hand, you will see their face light up with recognition. They will respond "I am protected" or some similar catchphrase from the pusher bot prank. Thus, you will know that your target is a goon. Even if you had no previous experience with this person, you will instantly know that you share a deep personal connection.
Use this secret keyword wisely...and be prepared for the full onslaught of goon humor if you choose to use it.