I started noticing these last month in two places around town so far. In both places they are in series and span about two blocks. I parked today, took a walk with the camera, and got this set. What could they mean? Fertile ground for a conspiracy, or maybe just some freak-o advance advertising for something that will come later.
Here they are all on one side of the street. This is the entire series in order heading south to north. I think since last month two have been taken, but this is what remains.