The world is full of placenames that carry enough secondary meanings to entice people to loot local signage. A simple and somewhat crass example would be Ragged Ass Road in Yellowknife, Canada, where the city had to weld the sign to the post. They also started to sell replicas of the sign locally, so people would have an alternative to theft. 

In a similar vein, the sign for Butt Hole Road in England was also a frequent victim of theft, as well as a welcome sign for the wonderfully named village of Shitterton. In the case of Butt Hole Road, it was ultimately renamed to Archers Way, after residents grew tired of both the constant theft and no doubt endless jokes about the area. The people of Shitterton were more resolute, instead having the sign chiseled into a massive stone that the average thief might struggle to steal. Seems like a potential plot for a pretty low-stakes heist movie. 

As one can imagine, the United States isn’t immune from this plague as well, as any sign with 69 or 420 is subjected to frequent theft. Mile markers that read 66.6 get stolen quite often as well, though it seems like a simple solution would be to move them just 0.1 of a mile away. Though one must expect that whatever contractor is responsible for replacing it is pretty happy with the whole situation. 

Like in the United Kingdom, some places just have less-than-fortunate names, such as Harry Baals Drive in Fort Wayne, Indiana, where the sign, inevitably, used to get constantly stolen. It was replaced with a sign reading "H. W. Baals Dr," which may have somewhat alleviated the issue, but it just underlines the fact that anything remotely recognizable, like a sign denoting “South Park,” or anything vaguely humorous will end up taken. 

Commercial signs tend to be stolen less often because they are generally not as “interesting” to people with an inclination for larceny. Both ancient Rome and China both had examples of businesses advertising a brand or events using publicly visible street signs. In China, sign printing would include a trademark, most famously a white rabbit, to designate that this shop has items from a specific manufacturer. 

While these days we might be annoyed at the bombardment of signs, ads, and neon lights, Medieval shopkeepers and craftspeople were often explicitly ordered to display signs. In England, Richard II passed a law that stated "Whosoever shall brew ale in the town with intention of selling it must hang out a sign, otherwise he shall forfeit his ale," although this was more to help inspectors quickly find locations that brewed alcoholic beverages.

Originally, these signs would designate just what sort of thing you could buy inside, but in larger urban areas, as there would be multiple of the same store, businesses started to develop their own names and symbols to stand out from the crowd. Over time, many would display royal coats of arms to fake royal endorsements, until laws were passed to specifically prevent such manipulation.