- I love those rocks.

Yes, they're my friends.

I've known them forever.

So I take it very personally when people deface them and put terrible things on them.

- [Pamela Watts] Artist Holley Flagg has good reason to be protective of the picturesque rocks that define the 400 miles of Rhode Island's rugged coastline.

It's the view right outside the window of her third floor studio in the home her family has lived in for generations.

This was her childhood playground, - Grew up there, picnicked there, ran all over the rocks.

Know them like the back of my hand.

Also, I'm an artist, so I really love the beauty of them.

They're just unique rocks.

- [Pamela Watts] Raw, natural beauty is the bedrock of Flagg's work.

She's currently painting watercolors of Nebula from images captured by NASA's Hubble Space Telescope.

- This is Madam Butterfly.

- [Pamela Watts] Flagg is also a graphic artist creating designs for the Metropolitan Opera and the Museum of Natural History in New York.

But when so-called Street Art spray painted graffiti began proliferating along the rocks in her Narraganset neighborhood, the artist saw red.

- When you see somebody defacing them and writing their personal messages, which they think are going to be immortal all over the rocks, it's really upsetting to me and I, it's visceral.

- [Pamela Watts] Flagg was so outraged, she took justice into her own hands, forming the citizen's group, Anti-Graffiti Vigilantes.

- Just lightly brush over it like this.

- [Pamela Watts] Armed with only a brush and cans of latex house paint, she started taking a swipe at what she views as crimes against nature.

But what might critics think of their attempts to obscure the colorful doodles of others?

You see this as restoration of nature.

Others might see it as destroying urban art.

They say graffiti is an art.

What do you say?

- I say, go somewhere else and do your urban art.

And some people do really fabulous art, and I respect that and I admire it, just not in nature.

Let nature be nature.

Let see what color you got.

That's it, looks good.

- [Pamela Watts] Soon, a small posse of like-minded volunteers took up the charge.

Their restoration of these geologic gems requires wiping out the words and pictures in such a way it tricks the eye.

Instead of just a coverup, the rocks magically appear as they once were.

- I judge how close I am with the color that I've put on.

Really the key to a good job is to just feather it in really lightly.

Let the texture of the rock come through.

- [Pamela Watts] At first in an effort to be truly natural, the Anti-Graffiti Vigilantes tried to clean off the spray paint with wire brushes, even chemicals.

Nothing worked because the rocks were too porous.

The beach was too steep for sandblasting equipment, so.

- I know about painting and colors and nuance.

So we said, let's try, let's try painting over it, camouflage.

- How did you come up with this technique of camouflage?

- I didn't really think about it.

I mean, it was just very basic.

How do I make this look like the rock there?

I keep adjusting my paint colors as I go along.

You keep doing it until you like the effect that you've gotten.

- Because the rocks are different.

Some are granite, some are brown.

So you have to pick the colors.

- Yeah, and you do many colors over one little area of rock.

You don't just say, okay, this rock is gray, here's gray.

- Get a big dry brush and you just smash it into the rock.

I think it's more just feel than anything.

- [Pamela Watts] Joan Pavlinsky is a social worker, artist, and ardent Anti-Graffiti Vigilante.

- It's just a way of kind of making my own mark by marking over other people's work.

If you think about what art really is, it's mark making, you know, and hopefully we're creating an environment so that it's not going to be, you know, vandalized again.

- If we do a good job, then they can't tell where it was.

So that's what we're hoping that as you walk around here, you don't even think about graffiti.

It's just not what you came here to see.

- [Pamela Watts] Volunteer Marianne Chronley joined the Anti-Graffiti Vigilantes a decade ago.

Spring and Autumn, the band of avengers attack rocks at places like this along Black Point Trail at Scarborough North Beach, near the iconic remains of the 19th century mansion, Windswept, itself, the victim of vandals.

Chronley says they gather tips from informants.

- We watch for it, you know, and we hear about it.

People tell us about it.

When we hear that it's down here, we say, all right, well, we got to get our crew together and come on down.

- [Pamela Watts] The Anti-Graffiti Vigilantes go to great lengths to disguise the work of vandals.

Sometimes hiking through outcroppings and sea spray just to reach their targets.

- We have a large canvas, you know, a large graffiti canvas, and you're like, oh, you know, this is going to take forever.

You just, there's like, no way we can do this.

Within like an hour or two, it's done.

And you sit back and you're, I am often amazed myself.

- [Pamela Watts] These before and after pictures are testimony to the results.

Some photos we can't share because of objectionable words and images.

- The last thing you want to do when you had a hard day at work, you're out with your dog, you're with your kid, you're walking along the path and you see a large pink profanity like written on a rock.

You know, it's like, it just, it just sort of just creates this energy that's just drains you, I think.

- [Pamela Watts] The Anti-Graffiti Vigilantes say, those who come to stroll along the shore often voice appreciation and sometimes offer to help.

- A lot of people say, oh, I'm so glad you're doing that.

They sympathize and they totally agree with how we feel.

And then other people are totally blank, they have no clue what we're doing, and they just think there's a bunch of weird people.

- [Pamela Watts] Undaunted, the Graffiti Vigilantes keep chipping away, true rock stars of Rhode Island's shores.

- It's with great satisfaction.

So as I step over some of the rocks, I can think, ah, we've been here and we did that one, and we've done that one many times.

We'll probably have to do it again.

But it's nice to know that we were here and it looks better now.

- I want you to be able to look at these beautiful rocks and not read things.

No words, no images.

Just say, wow, these rocks are really beautiful.

This ocean is beautiful, and we are so grateful to have it.