Paparazzi and others who harass the children of public figures will face stiffer penalties under new legislation in California.
A bill signed into law by Governor Jerry Brown boosts penalties for actions that include taking photographs and a video of a child without consent and in a harassing manner.
Media organisations, including the California Newspaper Publishers Association, had opposed the move, which increases penalties for harassing children because of their parents' job, on the grounds that it was overly broad and could restrict the legitimate newsgathering activities of reporters and photographers.
However, Mr Brown, who dated rock singer Linda Ronstadt during his first stint as California governor in the 1970s, approved the measure without comment on Tuesday.
It means those caught breaking the restrictions now face a maximum sentence of one year in jail - up from six months- and a fine of up to $10,000 (£6,252) instead of the current £1,000 (£625) financial penalty.
The bill was given a boost when Hollywood mothers Halle Berry and Jennifer Garner gave it their support at a California legislative hearing in August.
Berry said her daughter had been intimidated by aggressive photographers who followed them daily, often shouting as they snapped pictures.
Welcoming the legislation, she said: "I started this fight with a great deal of hope and a bit of uncertainty so I cannot express my immense gratitude that Governor Brown has recognised, and acted to remedy, the plight of children who are tormented because of the identity or prominence of their parents.
"On behalf of my children, it is my hope that this is the beginning of the end for those overly aggressive paparazzi whose outrageous conduct has caused so much trauma and emotional distress."
Garner, who has three children with actor-director Ben Affleck, said she and her children were followed everywhere they went.
"How often do we see a tragedy unfold and say 'Oh, there were so many warning signs. Why didn't anybody pay attention?'," Garner said at the time. "I am asking you as a parent to pay attention."
The measure also will help protect the children of police officers, judges and others who might be susceptible to harassment or unwanted attention due to their parents' occupations.
The hounding of celebrities by paparazzi has long been identified as a risk in Los Angeles.
Nicole Kidman said she was left "shaken" after being knocked to the ground by a cycling paparazzo in New York earlier this month.
And Justin Bieber called for new laws to protect people from the paparazzi earlier this year after a photographer was killed taking pictures of his sports car in Los Angeles.
A 2010 law increased penalties for reckless driving by people trying to get photos for commercial gain.
Two charges against photographer Paul Raef, who became the first person to be charged under the 2010 law in connection with a high-speed chase of Bieber in July 2012, were thrown out by a judge who ruled the legislation was overly broad and violated the First Amendment.