In 1982, Ozzy Osbourne allegedly urinated on the Alamo in San Antonio. We're trying to shame the Prince of Darkness here, but people don't always respect landmarks. Urbanist has created a list of the 9 most vandalized landmarks in the world, which illustrates just how ugly people can be at times.
Jim Morrison's grave at Père Lachaise Cemetery in Paris is heavily tagged with both messages of rememberance and graffiti. The Paris Catacombs have also been covered with graffitti, including a huge mural of SpongeBob SquarePants.
Stateside, people have been fucking with the Hollywood sign for years.
In Seattle, people have taken to leaving graffiti on the Fremont Troll, prompting the city to clean it up time and time again. The lone example of welcome vandalism also comes out of Seattle in the form of the Gum Wall, which was created when patrons tired of long lines took to sticking their gum on a wall in Post Alley. When theater attendants quit scraping the gum off in 1999, man-made art was created.