If you visit the Pakistani town of Rawalpindi on Google Maps today, you're in for a shock - you will be greeted by an image of the Android "Droid" mascot urinating on Apple's logo.
Google and Apple might be bitter rivals, but Google insists that its employees aren't to blame.
A spokeswoman for the company told me that the bizarre image was created by Map Maker: A Google app that lets users update and contribute to its Maps to improve their accuracy. These edits are supposedly reviewed by other users to ensure there's no abuse, but this one apparently got by unnoticed.
Of course, it's possible that the image was created by an impassioned employee (someone definitely spent some time on it.) But MapMaker can definitely be used to add erroneous information to Google Maps by anybody.
Shortly after the Rawalpindi prank first came to light, another message appeared in a nearby forest, which we were first alerted to by British political blog Guido Fawkes.
MapMaker is simple to use. Just navigate to Google.com/mapmaker, log in with your Google account, and you can immediately start making changes. There's an array of options to choose from - roads, sand dunes, drinking water, parks, and more - giving you a broad palette with which to create your art.
I headed over to Kulob, a town in Tajikistan I once visited, and left Business Insider's mark on the outskirts, using a reservoir and a forest as my mediums.
My changes aren't live yet if you just visit Kulob on Google Maps, because they still need to be reviewed by other users. But it would be easy enough just to register another Google account to do so. And this morning's graffiti - and the follow-up message left in the forest - show just how easy it can be to make changes that slip through the net.
We've asked Google for more detail on MapMaker, including how many user reviews are required before a change is set live on Google Maps. We'll update this story when it responds. And if Kulob suddenly gains a new BI-shaped piece of terrain.