Prank phone calls, for the most part, are a harmless joke, but at times, they end up costing towns and taxpayers tens of thousands of dollars. The "swatting" trend has been gaining steam across New Jersey and the country, sending large-scale law enforcement responses to a scene for absolutely no reason.

The latest case in Keyport this past weekend followed three earlier cases in New Jersey over the past several weeks. A school was locked down in Holmdel, a neighborhood was sealed off in Upper Freehold and a gathering at a video store in Clifton was interrupted by the arrival of SWAT teams and hostage negotiation personnel. In each instance, the initial call was a hoax.

Police SWAT scene in Pennsylvania last month. (AP Photo/Matt Rourke)

Commenting on the Clifton incident, Lt. George Rosenthal of the Passaic County Sheriff's Office said costs for that type of response can reach $5,000 an hour.

"We need more than just some of the personnel at hand," he said. "With something of this nature, we start to recall personnel. That's only our agency too."

Police did not realize they were hoaxed until the video game store owner, cooped up inside, told them there was no hostage situation to solve.

But Rosenthal said once that initial call is made, all hands are on deck. There's no time to determine whether the call is real or fake.

"You don't want to fall into some kind of complacency where this is the boy that cried wolf," he said. "But these resources are dedicated to saving lives, and here they are standing by because somebody made a prank phone call."

Following the string of New Jersey incidents, a once-stagnant bill in the state legislature is now headed to the Assembly Homeland Security and State Preparedness Committee. The legislation would hike the punishment for creating a false public alarm.

Assemblywoman Annette Quijano (D-Elizabeth), chair of the committee, said law enforcement will be invited to the hearing, which does not have a date yet.

"This needs to have serious consequences," she said. "It's straining budgets for a game, a joke."

According to Sgt. Jeff Flynn of the New Jersey State Police, they have not identified a swatting trend in the areas they patrol. However, State Police handled the early April incident in Upper Freehold.

"Who placed that 9-1-1 call is currently under investigation," Flynn said.