Graffiti has existed since ancient times with examples dating back to Ancient Greece and the Roman Empire.

In modern times, spray paint, regular paint and markers are the most commonly used materials.

Although the defacing of property is a crime punishable by law, many artists choose to express themselves this way.

This form of art is also used by some for communicating social and political messages.

For this post, we've compiled a collection of 40 striking examples of Graffiti Art. Know of any other great examples? Please post them in the comments' area.

Compiled exclusively for WDD by Jarkko Laine.