"An important civil right of privacy is involved," Gatti said. "The lawsuit seeks to establish the extent to which individuals are protected against technologically enhanced encroachment into their private property."
Alonzo Wickers, a 1st Amendment lawyer who represents television networks and newspapers, including the Los Angeles Times, said it will be difficult for Streisand to prove an intrusion into her privacy or a violation of the anti-paparazzi law because she does not appear in the photograph.
"If it were a picture of her sunbathing topless, they might have a case," Wickers said. The legal standard, he said, is capturing an image that would be highly offensive to a reasonable person.
"It's very hard to argue that the appearance of her backyard would be highly offensive to a reasonable person," he said. "The standard is not what's offensive to a reclusive celebrity who is highly concerned about her privacy and security."
Kenneth and Gabrielle Adelman, Caltech graduates who retired in their 30s after selling two start-up software companies for $445 million, have been using digital photography to snap pictures of every inch of the coastline.
She flies their helicopter while he leans out the side snapping pictures in an effort to record images of every cliff, beach, rocky outcropping and sign of development along the coast.
Adelman said he takes his pictures from an elevation of 500 feet in public airspace over the ocean, shooting back toward the shore -- using a standard lens, not the enormous telephoto lenses preferred by paparazzi.
The lawsuit contends that the high resolution of the photographs allows Web site browsers to click their way to a considerably larger and more detailed view of Streisand's home. Browsers can also pick out Streisand's home because the photo includes a caption that identifies it as "Streisand Estate, Malibu."
In two letters to Adelman, Streisand's lawyers demanded that he remove the photograph or face legal consequences, including punitive damages and attorneys' fees.
Adelman refused, citing protection under the 1st Amendment to publish such photographs.
He said he didn't target Streisand's home and didn't add the caption below the photograph. He said he made the Web site interactive so that anyone from the public can add captions to any photo to help identify various features along the coastline. Someone did, he said.
He also noted that his Web site does not list Streisand's address, unlike other Web sites that provide virtual tours and maps of homes of the stars, including hers.
Adelman said his project is an effort to establish a photographic record of the entire coast and that he doesn't want to begin exempting certain areas. The only place he has yet to photograph is Vandenberg Air Force Base, which has so far denied him permission to fly by on the grounds that his photos might pose a security risk.
Adelman said about 620,000 viewers have inspected the Web site so far, including university researchers and local, state and federal agencies, among them the California Coastal Commission and the U.S. Geological Survey.
A status conference on the case is set for Aug. 28 before Superior Court Judge Allan J. Goodman.
