Los Angeles (CNN) -- Ben Affleck's children are "freaked out" by photographers who camp near their home and follow them in public, the actor said.
Affleck and his wife, Jennifer Garner, hope a beefed-up California law with keep the paparazzi at a distance when it takes effect on New Year's Day.
"My kids aren't celebrities," Affleck said in a wide-ranging Playboy interview. "They never made that bargain."
The law, which Garner joined Halle Berry to lobby for, doubles to a year the jail time a photographer can get for harassment that "seriously alarms, annoys, torments, or terrorizes" children. The law applies to children under 16 who are photographed because of their parent's occupation.
"The tragic thing is, people who see those pictures naturally think it's sweet," Affleck said. "They don't see the gigantic former gang member with a huge lens standing over a 4-year-old and screaming to get the kid's attention."
Affleck and Garner have three children: Violet, 8, Serafina, 5 next month, and Samuel, who turns 2 in February.
"The kids are always looking down because they're freaked out and scared of these people," Affleck said. "And so they yell. Which is fine if you're Lindsay Lohan coming out of a club, or me, or any adult. With kids, it's tasteless at best."
Affleck recounted a case five years ago when a man was charged with stalking his family after hiding among the pack of paparazzi that followed his children to nursery school. The stalker "who had threatened to kill me, my wife and our kids showed up at the school and got arrested," he said. "I mean, there are real practical dangers to this."
A Los Angeles judge ruled the man was mentally incompetent to stand trial. He was committed to a mental health institution and ordered to stay away from the family for 10 years.
The California law does not punish websites, newspapers or magazines for publishing photos of children taken in violation of the law.
"A lot of these photographs are being bought by legitimate magazines," Affleck said. "In the UK, they have a good system: If you take a kid's picture, you have to blur out the face. It protects the privacy of children, any child. I wish we would do that here, though I don't expect it."
He wants a "bubble of safety" around his children, with cameras staying at least 100 feet away, he said. "They all have 300-millimeter lenses. I'm a photographer myself, and I can tell you with complete confidence that you can get a fine picture."