We've all seen it - the photo of a famous celebrity caught unaware. He might be lighting a cigarette in front of a child, or she might be hiking up her swimsuit on the beach to cover something that should not be showing. In many of these celebrity photos, the celebrity is scowling or angry.

These photos are the work of the paparazzi. The paparazzi are photographers who take photographs of celebrities in return for money from magazines, newspapers and television shows.

The word "paparazzi" comes from the name of a character in a movie. That character - Paparazzo, in the 1961 movie "La Dolce Vita" - is styled after a real Italian photographer named Tazio Secchiaroli. Secchiaroli made a name for himself as a street photographer in the 1950s. He was the first photographer to start taking pictures of stars and politicians on the street. Before that, just about every photo of a star in a newspaper was a publicity photo.

Why do the paparazzi do what they do? At the root of it is the fact that many people have an insatiable appetite for information about celebrities. Photos and videos of celebrities sell magazines and draw viewers to TV shows. Therefore, editors are willing to pay money for photos. That money gives the paparazzi the incentive to do what they do. If a photographer takes a good photo of a celebrity in a compromised position, that photo can be worth thousands of dollars. Photos of celebrity babies and celebrity weddings also can earn big bucks.

Really good paparazzi are a lot like private detectives, developing a network of informants who help them locate their prey. For example, a photographer might pay hair stylists, restaurant employees, caterers and so on for information about celebrities.

Once a member of the paparazzi knows where the celebrity is, it is time for technology. A good camera with a big zoom lens often can be helpful. In most cases, if the paparazzi is taking a picture of a public figure (like a celebrity) in a public place, then it's legal. This allows a photographer to stand on public property and capture a picture of a celebrity using a telephoto lens. Sometimes the paparazzi will go to great lengths. The paparazzi can use helicopters, boats - just about anything they can think of to get a good shot.

If you are sympathetic to the plight of celebrities, you might be wondering whether there is anything that can be done to control the paparazzi. Some countries have taken action. In France, for example, there are laws governing the paparazzi. California has some controls as well, enacted in the wake of Princess Diana's death. It may take another death to get more far-reaching legislation passed.