They lurk in bushes, camp out in cars and hover in helicopters. Some are brazen enough to openly brandish their cameras, like old Western gunslingers.

They may be hated, but their work — candid pictures of celebs in unguarded moments — is coveted. They are the paparazzi, purveyors of pix that are the lifeblood of the weekly star-tracking mags and tabs. Their photos demand huge sums of money and are circulated worldwide. And as the public hunger for such glossy grist has grown they've become ever more relentless and ruthless. But starting Jan. 1, there'll be some new reins on the paparazzi parade.

That's when a new California law goes into effect that increases penalties against overly aggressive photographers — dubbed "stalkerazzi" — who forcefully thrust their cameras into famous faces or crash their car into a celebrity's vehicle. They'll now be liable for three times the damages they inflict, plus lose any payments their published photos might earn. Publishers can also be held liable.

"Now the paparazzi are going to have to think twice about chasing down a celebrity anywhere in California," said Assemblywoman Cindy Montanez, who drafted the bill, which was signed into law in October by Gov. Arnold Schwarzenegger. (The former actor had an infamous paparazzi moment in 1998 when they used their cars to surround his SUV as he and wife Maria Shriver picked up their child from school.)

The new law was inspired by a rash of recent celebrity car chases, Montanez said. In May, a photographer following Lindsay Lohan crashed into the actress' car in West Los Angeles. The photographer was booked for assault with a deadly weapon, but prosecutors found insufficient evidence to press charges.

In August, actress Scarlett Johansson was involved in a minor car crash in a Disneyland parking lot after being followed by paparazzi, and actress Reese Witherspoon said photographers tried to run her car off the road in April. No criminal charges resulted from those incidents, but the Los Angeles District Attorney's office continues to investigate paparazzi photographers' aggressive tactics, said spokeswoman Jane Robison.

Montanez said the new legislation "targets those who break the law in their attempt to get the photograph."

While some celebrity shooters think the new law is needed to curb increasingly aggressive behavior, others call it unfair and unnecessary. And it may even be unconstitutional.

Though the legislation is aimed at paparazzi photographers, it could have "a chilling effect" on newspapers and other media, said Jim Ewert, legal counsel for the California Newspaper Publishers Association.

"This law now gives [celebrities] the ability to quash a photograph, and potentially a story [resulting from the photograph], with a frivolous lawsuit in an attempt to keep the public from being informed," he said. "The constitution demands a little bit higher standard before the government puts the kibosh on a newspaper's ability to publish that story."

Montanez insists the law was "specifically crafted in a way so there is no infringement on the rights of journalists."

"This is about paparazzi who wait and hunt the celebrities, their prey, until they catch the celebrity in a state of compromise," she said. "They engage in assaultive behavior, and we can't condone that."

Longtime celebrity photographer Frank Griffin, co-owner of the Bauer-Griffin photo agency — which bills itself as "The Hollywood Hunt Club" — said existing laws already cover attempted assaults and that the new legislation unfairly targets celebrity photographers.

"Why should there be different standards for a hard-news photographer and a celebrity photographer?" he asked.

With the proliferation of photo-filled, celebrity-centered magazines, more paparazzi have emerged to fill the pages with images of the rich and famous. The more exclusive the photo, the bigger the paycheck, said former celebrity photographer Brad Elterman.

Shots of Ben Affleck and Jennifer Garner with their new baby, for example, could be worth $500,000, he said. Even less-exclusive pics of hot stars can sell for $10,000 or more.

"The business is driven by money," Elterman said. "The guys who take the pictures don't care how they get the photo because they have nothing to lose."

Jim Ruymen, a Los Angeles photographer for 30 years who worked as "a photojournalist by day and a paparazzo at night," said paparazzi photography has always been intrusive, but increasing competition has led to more in-your-face tactics. There might be "15 to 20 cars outside someone's house, waiting for them to leave so you can chase them down," he said.

"Part of the paparazzi act is you really have to have no conscience. You've got to rein these guys in, so we don't have a Diana here in Southern California," he said, referring to Princess Diana, who was killed in a Paris car crash in 1997 as paparazzi pursued her vehicle. Investigators later found that the driver of Diana's car was intoxicated and speeding.

Celebrities are likely to appreciate the new legislation, though none of their publicists returned calls for comment here.

George Clooney, an outspoken defender of the first amendment yet a critic of overzealous photographers, has said that being photographed is the price one pays for celebrity, but some tabloids take things too far.

"If you say to someone, 'I'll give you $400,000 for the first picture of Madonna's baby,' there are lots of people who are willing to break the law to do that," Clooney said in a cable news interview in 2003.

The new legislation amends a bill passed in 1998 that established the concept of "constructive trespass" for photojournalists. It said that using a long lens to capture an image of a person who had "a reasonable expectation of privacy" was tantamount to trespassing.

Ewert, counsel for the California Newspaper Publishers Assn., questioned the constitutionality of that law, but it has not been challenged in court, he said. Laws are presumed valid until challenged.

The new legislation, which expands what constitutes invasion of privacy, "is probably even more unconstitutional, if that's possible," Ewert said.

"We don't apologize for the behavior of the paparazzi," he said. "But this law attempts to stop that conduct with a very broad brush."