Graffiti is as old as the written language. In fact...older. Some of what we know about ancient civilizations, we've learned from graffiti. Recently the bulkhead (that's a wall for you land lubbers) and bunks from a troop ship that carried soldiers to war ended up in a Naval Museum. The Navy put on display the walls filled with not only the profane and risque but astute and philosophical observations. And sometimes the author's own tragic future. The only known source of the Safaitic language, is from 1st century B.C.E. graffiti and was found scratched on the surface of rocks and boulders in the deserts of Syria, Jordan and northern Saudi Arabia.
As a nation we spend hundreds of thousand of dollars every year removing and abating the blight of graffiti. In certain areas gangs use graffiti to claim ownership to a neighborhood and to spread fear. The counter-culture send political messages and the lone artists claiming their misunderstood, make their statements in spray paint.
If the graffiti on this wall survives all of us, if it is to survive our way of life, our language, our culture...how will a future civilization judge you and I? And just so you know...I really didn't see the naked woman until after I'd made the photo.