Kilroy Was Here

Long before the Internet made viral marketing a cinch, one long-nosed little character named Kilroy made his way around the world the old-fashioned way, becoming a legend among the millions of military men and women who served during World War II.
The rudimentary doodle, which featured a balding head peering over a wall along with the tag "Kilroy Was Here," popped up in unexpected places across all of the theaters of war visited by American troops.
While competitions to inscribe the graffiti in obscure locations kept the battle-weary soldiers busy and its appearances kept them inspired, the mysterious Kilroy character had Japanese intelligence officers and even Hitler himself worried over the seemingly ubiquitous guy.
Reportedly spurred by an American dockworker, the "Kilroy Was Here" fad was an iconic part of World War II and 1940s lore. (Source: Live Science)
It didn’t stop with world war two GI’s. The Korean War and Viet Nam war saw Kilroy pop up in the most unlikely places. And now he appears in Iraq, Kuwait, and Afghanistan. He just won’t go away.
On the home front, kids, especially those in high school or college, used Kilroy to harass or confuse teachers or supervisors,