Legislation approved by the state Senate on Thursday would force pranksters who make hoax 911 calls like the ones used to target celebrities pay for the cost of police responding to the fake emergencies.

The practice is commonly known as 'swatting' because police often respond to what appears to be a dire emergency by mobilizing their Special Weapons and Tactics teams.

The trend started in other states but has been increasingly used in the Los Angeles area to target celebrities in an effort to draw publicity, said Sen. Ted Lieu, D-Torrance.

Callers earlier this year falsely reported violence or intruders at the homes of Tom Cruise, Justin Bieber, Ashton Kutcher, Chris Brown and other stars.

"This is becoming a phenomenon," said Sen. Steve Knight, R-Palmdale. "We have a lot of celebrities.... 'Swatting' these people seems to be the way to get into the news."

Lieu said such calls are expensive, disruptive and dangerous.

"It's a massive drain of law enforcement resources," he told fellow senators. "You can imagine how you might cause injury or death .... You have all these officers with guns drawn going to that home."

His SB333 would require that the pranksters pay costs that Lieu says can top $10,000. If the culprit is a minor, his or her parents would be responsible for reimbursing law enforcement.

While no senator opposed the bill, defense attorneys have argued that the measure isn't needed because existing state law already allows law enforcement to seek restitution for the cost of an unnecessary emergency response.

An Assembly committee is considering a different approach. AB47, by Assemblyman Mike Gatto, D-Los Angeles, would impose a penalty of up to a $2,000 fine and a year in jail, with increased penalties if the call results in injuries or death.

Senators passed Lieu's bill, 33-0, sending it to the Assembly.