Feb. 28) - Oh, for the good old days when all we worried about was Big Brother government watching us. Too late: Now we have Little Brother to contend with, too - and he's got a camera phone.

Little Brother could be a fed-up straphanger on a subway, a sneaky student in class, maybe a ticked-off guy in the audience. Or a vengeful ex-lover or jealous friends looking to embarrass an American Idol contestant.

Here in YouTube world, whether you're a celebrity or a nobody, privacy can be a disappearing luxury, thanks to the technology in every pocket. While you're fretting about whether the government is listening to your phone calls, your neighbor is sneaking pictures of you on his cellphone or his digital camera - and sharing them with the world.

"Pandora's out of the box," says Susannah Stern, a University of San Diego professor who studies modern communications. "If the government is tracking calls, most people aren't going to feel the repercussions. They're more affected if a compromising photo gets on the Internet - that's a personal invasion they can see."

In the old days, kids would go on spring break, get drunk, take off their clothes, and few people would know. Now those kinds of pictures flicker 24/7 on the Internet, which means anyone on the planet can see them, including the college admissions officer, the potential employer or the voters in some future election - like the one on American Idol.

As Idol semifinalist Antonella Barba is learning: First, mildly risqué photos of her naked but strategically covered, some taken for a calendar for her boyfriend, turned up on the Internet; now more explicit photos of a woman said to be Barba in a sex act have surfaced. Her friends say it's not her - but it looks like somebody has been betrayed by a lover with a camera. Even if it's not her, Barba has been in tears about the photos. She is still in the Idol competition - for now.

"The days when something happens in front of a crowd and it's not captured on camera are over," says Josh Calder, a trend tracker at Social Technologies. "We have to assume anything we do in public is potentially going into the public record."

But is that enough to make people behave better?

"We are in the transition period," says Harvey Levin, proprietor of the entertainment news site TMZ.com. There's a recognition that things are different, "but it's still new enough to not adjust our behavior."

Which is good for TMZ: It broke the story about Mel Gibson's anti-Semitic rant after he was arrested for drunken driving. The episode hurt the actor/director, but it might have been worse if there were video. "Seeing it in writing is one thing, seeing it with flesh and blood attached is different," says Levin.

A couple of beauty queens know all about that. Miss USA Tara Conner tearfully acknowledged underage drinking and late-night clubbing, but there were no images of her dancing drunk on tables. She kept her crown. Then Miss Nevada USA Katie Rees tearfully admitted that she got drunk and posed for raunchy photos years before her pageant win; the photos turned up everywhere. She lost her crown.

Every day, new pictures or video pop up to amuse, shock or ruin. There are pictures of couples having sex (a cheerleader and her boyfriend exposed after her camera phone is stolen). There are pictures of people behaving badly (Kate Moss appearing to snort cocaine, Lindsay Lohan, Britney Spears and Paris Hilton partying without panties). There are videos of people saying things they shouldn't (Michael Richards shrieking the N-word at a comedy club).

"Your privacy is basically over," laments Ty Tindell, 29, of Howard County, Md., who found himself on YouTube after he was recorded on a camera phone at a Mariah Carey concert "having fun and acting a fool" after a few drinks. "It's an invasion of privacy," he says, noting that camera phones were banned at the concert. "There's no camera-free zone anywhere."

There's no doubt camera phones are increasingly unavoidable. By one estimate, there are 2 billion around the world, about 88 million of them in the USA.

"It's really hard to buy a cellphone without one," says Kevin Wehr, a sociologist at California State University, Sacramento. "The history of being caught on videotape is not new - think of Zapruder and Rodney King. What's different is the ubiquity." And speed.

"If I take a picture on my cellphone here on the ski slope, I can e-mail it to my office and it will be in the hands of, say, Chinese publishers in maybe 10 to 15 minutes," says Gary Morgan, co-owner of celebrity photo agency Splash News, calling via his cellphone from a working vacation on the slopes. "Technology has far outpaced the legislative and ethical and moral behavior of society."

A year ago, Splash set up PeoplePaparazzi.com, seeking camera phone images of celebrities captured by "citizen paparazzi." So far, only a tiny percentage of the images have been of good quality worth selling, such as pictures shot of Brad Pitt and Angelina Jolie and their kids in Canada, which fetched thousands for the shooters.

Gawker.com, the gossip site, runs Gawker Stalker, which tracks celebrity sightings around Manhattan called in by ordinary schmoes. Most of the pictures aren't usable, but when they are, "they add a whole new dimension to gossip," says Gawker editor Emily Gould. "It's a totally different experience reading about someone canoodling at a nightclub and seeing a grainy cellphone video of, say, (a celeb) getting out of a car and vomiting."

The potential menace to celebs, whose privacy is already compromised, should be obvious. "It must be a frustrating time to be famous, knowing you not only have to worry about the paparazzi with the telephoto lens, but the guy on the next barstool with the latest Motorola," says Mark Donovan, senior analyst at the new-media tracking firm M:Metrics.

The non-famous, especially teenagers, may not get this yet. "I don't think their behavior is going to change, but how they use the technology might," says Stern, who studies young people's online behavior. "Right now, anything flies, but social conventions will develop that limit when it's cool and not cool to take pictures of each other."

In some cases, camera phones are used to enforce social conventions, as with the South Korean woman known as Dog Poop Girl, whose refusal to clean up her dog's mess on the Seoul subway was captured and posted; shame and humiliation followed. In Manhattan, commuters have whipped out their camera phones to snap flashers on the subway, then posted the pictures, hoping to at least shame the perverts, if not get them arrested.

Few people object to these uses, or to citizen journalists documenting news events, such as the London subway bombings in 2005. Even the capturing of Saddam Hussein's execution and ex-Sen. George Allen's "macaca" moment provided a public service of sorts.

Nevertheless, here's one possible peek at the future: More camera phones, more camera phone images, more people watching camera phone images - and little control over any of it.

"We do get pleasure and pain from other people's embarrassment - it makes us feel better about ourselves," says Cal State's Wehr. "We see people's failings and we're relieved: Thank God I didn't get drunk and take off my clothes."