Leaving Los Angeles: Scarlett sees red after scrape with paparazzi

So it was that, last Thursday, Johansson noticed she was being followed by a posse of four-wheel-drives as she left her Hollywood home and started down Interstate 5 towards the theme park, a 45-minute drive away. She paid the $10 entrance fee to the Disneyland car park in the hope of losing her pursuers, but they followed her.

Unnerved, she started swerving her Mercedes and accidentally sideswiped a Daihatsu carrying a mother and her daughters. Ms Johansson immediately apologised profusely for what she had done, according to her publicist. She didn't lodge a formal complaint or attempt to press charges against the photographers, and nobody was hurt.

But the actress was in no doubt that they were at least morally responsible for the accident. "She has not been left alone since she has come back to the States," the publicist, Marcel Pariseau, told the Los Angeles Times. "At least two or three of them had been camping outside of her house for five days." Mr Pariseau added: "She's frustrated, she's left Los Angeles. She can't deal with it any more."

This is turning into the summer of dust-ups between celebrities and their camera-snapping pursuers. In June, the teenage star Lindsay Lohan - of Freaky Friday and Herbie: Fully Loaded fame - came into collision with a minivan near a Los Angeles shopping centre. The photographer at the wheel of the minivan was subsequently charged with assault with a deadly weapon (the vehicle).

In April, Reese Witherspoon of the Legally Blonde films said she had been chased across town from her gym by paparazzi who hemmed her in on a street in the Hollywood hills and only backed off after she appealed to a private security guard at the entrance to a gated community for help. Prosecutors announced earlier this month that the photographers involved in the incident would not face criminal charges.

The photographers argue that Hollywood celebrities - who love publicity when it suits them - have to accept that sometimes the media attention can't be tailored to order like room service in a five-star hotel.

In the Disneyland episode, the JFX Direct photo agency acknowledged two of its photographers were on the job but said their vehicle was at least 40 yards away and had nothing to do with the collision. Johansson does not appear to have disputed that version of events - only the appropriateness of being followed so relentlessly.

The Los Angeles district attorney's office is conducting a special investigation to determine whether the behaviour of the paparazzi poses a danger and whether there is a pattern, as some have alleged, of deliberately endangering celebrities to create situations conducive to more titillating photographs.

There is no doubt that the market for unposed shots of celebrities - and particularly prominent young actresses - has increased vastly thanks to the growing popularity of glossy celebrity magazines.

More photographers than ever are now in competition to snap pictures of young stars going shopping, or working out at the gym, or diving into their pools. Magazines such as US Weekly have taken to publishing photographs of famous people looking their very worst.