Here’s another sign common in my subdivision. It’s an Invisible Fence (r) sign, and in terms of semiotics — i.e. the study of signs, signification, and meaning — it’s surprisingly dense.
The sign is not a warning sign per se, but it does evoke several implied threats. The most obvious is the object contained by the invisible fence — a dog. Presumably a large and hungry one, a dog who would cross property lines without heed, were it not for the invisible fence reining in the roaming canine. The fence keeps the dog in and passersby safe.
The corollary to this relationship is that intruders who cross the “invisible” line enter into the dog’s domain — a dog perhaps so territorial that its owners resort to electro-shock to keep it in its place. Now, in this specific case, I saw the sign, but no dog. You’d think that as I crouched in front of this house, snapping a photograph, the dog would be baring its teeth, chomping at the invisible bit. But no, no dog in sight. Maybe it was locked inside. Maybe it had managed to chew its shock collar off and was free. Maybe the dog didn’t even exist.
So, the “Invisible Fence” sign is an updated version of the threatening “Beware of Dog” sign. And it too is effective even if there isn’t an actual dog.
Whether or not there is a dog, to intruders on the homeowner’s property, the “Invisible Fence” sign also sends the message that the owners are into sophisticated electronic systems. The words “Invisible Fence” dominate the sign, and it’s a recognizable name brand. The Invisible Fence company all but dominates the “electronic pet containment” industry. And who’s to say that these homeowners aren’t into other elaborate electronic apparatuses, say, an advanced home surveillance system keyed into the local 911 network? This system of invisible technology aimed at buttressing the us/them duality of suburbia is another threat implied by the sign.