tagged bridges,

mural-covered walls.

Graffiti pops up boldly throughout our cities.

It can make statements about identity, art, empowerment, and politics,

while simultaneously being associated with destruction.

And, it turns out, it's nothing new.

Graffiti, or the act of writing or scribbling on public property,

has been around for thousands of years.

And across that span of time,

it's raised the same questions we debate now:

Is it art?

Is it vandalism?

In the 1st century BCE, Romans regularly inscribed messages on public walls,

while oceans away,

Mayans were prolifically scratching drawings onto their surfaces.

And it wasn't always a subversive act.

In Pompeii, ordinary citizens regularly marked public walls with magic spells,

prose about unrequited love,

political campaign slogans,

and even messages to champion their favorite gladiators.

Some, including the Greek philosopher Plutarch, pushed back,

deeming graffiti ridiculous and pointless.

But it wasn't until the 5th century

that the roots of the modern concept of vandalism were planted.

At that time, a barbaric tribe known as the Vandals swept through Rome,

pillaging and destroying the city.

But it wasn't until centuries later that the term vandalism was actually coined

in an outcry against the defacing of art during the French Revolution.

And as graffiti became increasingly associated

with deliberate rebellion and provocativeness,

it took on its vandalist label.

That's part of the reason why, today, many graffiti artists stay underground.

Some assume alternate identities to avoid retribution,

while others do so to establish comradery and make claim to territory.

Beginning with the tags of the 1960s,

a novel overlap of celebrity and anonymity

hit the streets of New York City and Philadelphia.

Taggers used coded labels to trace their movements around cities

while often alluding to their origins.

And the very illegality of graffiti-making that forced it into the shadows

also added to its intrigue and growing base of followers.

The question of space and ownership is central to graffiti's history.

Its contemporary evolution has gone hand in hand with counterculture scenes.

While these movements raised their anti-establishment voices,

graffiti artists likewise challenged established boundaries of public property.

They reclaimed subway cars,

billboards,

and even once went so far as to paint an elephant in the city zoo.

Political movements, too,

have used wall writing to visually spread their messages.

During World War II, both the Nazi Party and resistance groups

covered walls with propaganda.

And the Berlin Wall's one-sided graffiti

can be seen as a striking symbol of repression

versus relatively unrestricted public access.

As the counterculture movements

associated with graffiti become mainstream,

does graffiti, too, become accepted?

Since the creation of so-called graffiti unions in the 1970s

and the admission of selected graffiti artists into art galleries a decade later,

graffiti has straddled the line between being outside and inside the mainstream.

And the appropriation of graffiti styles by marketers and typographers

has made this definition even more unclear.

The once unlikely partnerships of graffiti artists

with traditional museums and brands,

have brought these artists out of the underground

and into the spotlight.

Although graffiti is linked to destruction,

it's also a medium of unrestricted artistic expression.

Today, the debate about the boundary

between defacing and beautifying continues.

Meanwhile, graffiti artists challenge common consensus about the value of art

and the degree to which any space can be owned.

Whether spraying, scrawling, or scratching,

graffiti brings these questions of ownership, art, and acceptability

to the surface.