Half a century ago, when the paparazzi business was in its infancy, James Dean almost crashed his motorbike into a Hollywood photographer, Phil Stern, at an intersection on Sunset Boulevard. The pair struck up a conversation, went out for breakfast and initiated a happy, if brief, professional relationship.
Now, it seems, all semblance of amiability is gone. Just over a week ago, the actress Lindsay Lohan had her car rammed by a paparazzo in a minivan. The photographer was charged with assault with a deadly weapon (the minivan).
And Ms Lohan, the star of films such as Freaky Friday and Mean Girls, is now co-operating with a special unit of the Los Angeles district attorney's office that is anxious to crack down on rogue paparazzi.
Prosecutors are growing concerned about paparazzi misbehaviour that goes beyond the standard invasions of celebrity privacy. For several months, they have received reports of paparazzi, possibly working in concert, causing car accidents or using their vehicles to hem in a celebrity.
"The concern is that because of these hyper-aggressive tactics on the part of the paparazzi, someone is going to get hurt or killed," William Hodgman, the head of the district attorney's target crimes division, told The New York Times.
In April, the actress Reese Witherspoon said she was chased across town by paparazzi who hemmed her in on a street in the Hollywood Hills. They only backed off, she said, after she called to a private security guard at the entrance to a gated community for help.
The actress Cameron Diaz and the singer Justin Timberlake were walking with a friend and his dog when, they said, a photographer in a four-wheel-drive roared up, knocked the friend to the ground and then took pictures of the two of them rushing to their friend's aid. The photographs were published in the magazine US Weekly, with no mention of who caused the accident.
Photo agencies specialising in celebrity shots have been told that they are being watched. Photo editors typically say the reports of misbehaviour are overblown, or else are the work of rogue photographers.
There is no doubting, however, that demand for celebrity pictures - especially celebrities caught in off-duty poses - is soaring. Magazines such as US Weekly have recently taken to publishing photographs of famous people looking their very worst.
Public debate about the ethics of paparazzi is a recurring theme in Hollywood, just as it was in Europe after the death of Diana, Princess of Wales. In the past, celebrities have either tended to keep quiet about occasional invasions into their privacy or else lashed out on the spur of the moment. (Sean Penn and Alec Baldwin attracted considerable publicity by getting into fistfights with a photographer.)
Taking the legal route is a new departure, especially now that Mr Hodgman's office is looking at the possibility of filing felony conspiracy charges against photographers - a charge which, if upheld, would lead to a hefty prison sentence.
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