ST. PETERSBURG — Artist Derek Donnelly walked past the bars along Central Avenue, looked into his phone's camera lens, and cracked a mischievous grin that hid how angry he was.

As one of the muralists whose paint transformed downtown into a destination for street art, now defining the look of the city for TV commercials, travel brochures, tour groups and Instagram posts, he believes it's up to him to guard against people exploiting the murals.

The guy he was about to confront was flat-out stealing, in his opinion. Donnelly was broadcasting the encounter live on Facebook.

"Instead of hiding behind the computer playing this f----- game like we always play with these people, I figure it might be better to kind of look the beast right in the eyes," Donnelly said into his camera.

Then he climbed the stairs to Pop-Up Art Gallery & Tea Shop and fixed his camera on gallery owner Brenton Bruns II, standing behind a display of kratom powders and teas.

"You guys got prints of murals for sale?," Donnelly asked him.

• • •

You might recognize Bruns from Nat Geo's reality show Doomsday Castle about his preparations for the end times, or one of his many other past, local ventures: the members's-only club At Cost Bar; the failed-to-launch Rock 'n' Roll Bed and Breakfast, the website downtownstpete.com, or a highly profitable synthetic marijuana wholesale business, which he ran before a crackdown made "spice" illegal.

He left town for a while to try his hand in the marijuana business out in Colorado, he said, but now he's back in St. Pete with a new plan to sell art, and kratom, a legal, controversial and mildly intoxicating substance made from leaves.

Almost immediately, he infuriated artists with the project. Bruns stepped into a scene at a boiling point, when the popularity and economic value of the murals is colliding with questions over how to support the people who painted them.

Bruns plan for his "digital art gallery" was to showcase local photographer Chris Sheppard's photos of the murals on TV monitors, and sell prints of them for $40. The muralists would get $15.

Sheppard e-mailed artists to ask permission, but Bruns wanted to move faster than they were replying, Sheppard said. Bruns held a grand opening and projected the mural photos on a wall in an alley and on TVs. He had 100 prints made of the murals on canvas, even though no local artists had given him the OK.

VIDEO: 112 Tampa Bay murals in under three minutes

"Those were samples. I was never going to sell any of them without the artist's signature on there, never," Bruns said later. "I wanted something to show the artists, so they could see the quality."

Bruns posted photos of those prints on Facebook, inviting artists to come sign them.

Artist Chad Mize saw his work, and posted a widely shared comment calling out Bruns for reproducing his art without permission. He called a lawyer to send Bruns a cease and desist letter.

"Not hearing back from an artist does not mean 'go ahead'," Mize said. "That's not permission."

Artist Sebastian Coolidge responded publicly on Facebook, saying the reason Bruns hadn't heard back from him, is because he had zero interest in devaluing his artwork with poor quality prints sold for cheap.

Artist Jennifer Kosharek called the police and went to Bruns' gallery with an officer escorting her for safety, she said, but didn't see the prints when she got there.

• • •

Donnelly paid Bruns a visit in person.

In the video, Bruns looks stunned when Donnelly starts grilling him. Bruns explains no prints were sold, and says he's "currently negotiating with all the muralists."

"None of the muralists want anything to do with working for you," Donnelly tells him. "None of us know you, appreciate anything that you've ever done, because you're a complete scumbag. You have treated us all with little to no respect."

"I'm trying to help you guys," Bruns says. "To get you into people's homes."

Donnelly demands Bruns hand over the prints. Bruns counters by asking if Donnelly would like to sign the prints, so they can be sold.

Donnelly says he'll be back, with some friends, and exits. Bruns calls behind him, "Derek, so I guess you're not going to sign the prints?"

Donnelly rushes back into the gallery, and explodes.

"I'm going to sign your f------ face in a dark alley one of these nights with a spray paint can," he says.

• • •

This week, the video had at least 14,000 views. The vast majority of comments, including those posted by artists, are supportive or thankful for Donnelly.

Donnelly didn't see any of his own art in the photos that set him off, but he sees himself as a representative for those who are more creative than business savvy.

"This whole thing is making people question how the artists are supported and credited for beautifying this city," Donnelly said later.

He questions how money from various mural tours supports the artists, and even bristles at people posting photos of the murals without tagging or noting the artist's name — things he says mean a lot for artists' exposure, and ultimately their income.

Artists say over the years they've seen prints for sale online, or even in local coffee shops. Mize has seen bands use his murals on an album cover without permission. Kosharek has seen her murals on postcards for sale in St. Petersburg, and once inadvertently spotted an unauthorized print of her work hanging on a living room wall in the background of a Craigslist ad. The woman, who was selling a table, would not tell her where it came from.

• • •

If murals are in a public place, can't anyone make use of them?

That's a misconception, said John Tehranian, a copyright attorney at One LLP who worked on a case in which a street artist sued Moschino for designing a graffiti dress worn by Katy Perry.

Artists own a copyright on their original work the moment they create it in a tangible medium, such as paint on a wall, and that gives them exclusive rights to reproduce, display or distribute it. Technically, even taking a photo of a mural and posting it to Instagram could be an unauthorized reproduction, but that doesn't mean artists can (or would) sue tourists.

"A tourist snapping photos of murals for non-commercial purposes is a lot different from a professional artist taking high quality photos and then displaying them, digitally or otherwise, inside a gallery, which is a commercial enterprise," Tehranian said. "Even if a gallery is just displaying unauthorized (photos of murals) and not selling them, it could raise a serious legal issue."

Still, even if someone was clearly infringing, that doesn't make it worth lawyering up. Legal fees might be more than the case is worth.

The exception is if an artist has registered for a copyright with the U.S. Copyright Office. Then they can sue for statutory damages up to $150,000 per willful infringement, plus legal fees, regardless of value or profit. It costs as little as $35 to file.

"Each day, we all create hundreds of copyright works, ranging from our casual doodles and smartphone photographs to more deliberate artistic creations. But the copyrights to these works are rarely worth litigating unless you take the extra step of registering them," Tehranian said.

Legalities, though, aren't everything, artists say. It's about ethics, too. If you're using murals for a music video, or your yoga business' Facebook header, or as backdrops for your engagement photo business, reach out. At the least, give credit.

"Just be cool," said Kosharek. "There's a girl who sells used clothes, and uses a lot of murals for backdrops. She messaged me and asked for permission, and she always credits. I really appreciated it, and she's promoting the arts."

• • •

Bruns' gallery is still open, though someone stole his sign last week. He still has the prints, but says he'll hand them over to the artists if they come by. He's selling different works of art, with those artists' permission.

"I guess I'm sorry I tried to get this art, that I love so much, into people's homes," he said.

Since the video, someone made a Facebook page titled Brenton Bruns II Leave St. Pete and photoshopped his gallery's logo, with "pop-up" changed to "puke-up." He laughs about that.

Someone bought the domain name brentonbrunsisathief.com and made it redirect to a mugshot from 2007. In the comments, they gossip about his old arrests, and recent one, in April, on charges of grand theft and domestic battery. He said he looks forward to proving his innocence in court.

People call him a drug addict or say that he owes them thousands of dollars in wages. There is no shortage of people who say Bruns wronged them in one way or another. He chalks it all up to being a "disrupter," the type of business man who's more likely to ask forgiveness than permission.

He admits he's made mistakes, says he's been sober six weeks thanks to kratom, then changes the subject to his new project, DTSP TV. He approaches people on the street to ask what they love about St. Petersburg, and films the response.

EDITOR'S NOTE: This story has been changed to reflect that statutory damages for copyright infringement could equal up to $150,000 per infringement. An earlier version stated the amount as $250,000.