FLORENCE — A young person walks along a grocery store aisle carrying two gallons of milk when he suddenly jumps, smashes the jugs on the floor and flops into the muck.

A friend is videoing his every move. His antics almost immediately appear on YouTube or Facebook.

The prank is called “gallon smashing” and it has become a YouTube sensation.

Many who view the videos are laughing. Law enforcement and business owners are not.

“They call it a prank, but it’s a crime,” said Florence police detective Jerry Pearson, adding teenagers are involved in most of the videos.

Florence police have received two reports of the prank locally.

“We’re trying to let people know about this before it gets any worse,” Pearson said. “Local businesses are ready to pursue charges. They want these people held responsible, and they will be.”

Lt. John Zerbonia, of the Hannibal, Mo., Police Department, said the problem there with “gallon smashing” stopped after police began arresting the pranksters.

“I think it would have went on if we had not made the arrests,” Zerbonia said.

He said officers charged four juveniles and an adult this week with vandalism.

“They went to four stores and did this, then posted them on Internet sites such as YouTube,” Zerbonia said. “They thought it was funny, until they were arrested.”

He said the four orchestrated the events where they removed containers of milk or other liquid products from store shelves. They then purposely fell, causing the containers to break on the floor.

“It’s not fun and games, like they think it is,” Zerbonia said. “There is potential for other people to get hurt by this. What if someone walks down the aisle right after they smashed the milk and then slips and gets hurt. They don’t think of the problems this causes.”

Pearson said parents need to be aware that this is happening and about the consequences their children could face if they are caught.

“They have to realize what they are doing is illegal, it’s a crime,” he said. “They will be charged with criminal mischief, which is a misdemeanor, but whoever is charged will face a $1,000 bond to get out of jail.

“It’s not a laughing matter.”

Tom Smith can be reached at 256-740-5757 or tom.smith@TimesDaily.com.