Video is spreading of a group of teenagers on bikes threatening a man, some of them throwing rocks and one even landing a punch in downtown West Palm Beach.

In a video recorded Wednesday night, Matt Nelson says this is the second confrontation he has had with the group of kids at night in downtown West Palm Beach near City Place and Clematis Street.

This time he had his camera phone rolling.

“As I start walking, I’m yelling, 'Hey guys remember me?’” he says in an interview.

What ensues, Nelson said, is a punch to his back, rocks thrown at him and threats. Once he pulled out his pepper spray, they scrambled, video shows.

“It just has got to stop,” Nelson said.

He said kids on bikes have been riding downtown, terrorizing people, ignoring traffic laws for the last month and a half.

“When they’re together it’s the "Lord of the Flies" mentality. Where they just feed upon each other. They’re trying to impress each other,” Nelson said.

In the first incident Wednesday, he says he was walking with his 11-year-old daughter when a rider was headed toward her.

“So, I stopped real quick as I just went boom. Like that. Protected her, pushed her behind me and then both arms caught him right in the chest and then he went sailing into the bushes,” he says.

After he saw them a second time, he wanted video of them to hopefully bring the unruly behavior to an end.

“You get all of these little infractions, they will start to add up. You hold their parents accountable. That starts to add up,” Nelson said.

He passed along the videos to police who tell us they are working with the school district to help identify the kids and get in touch with their parents.