Imagine a scene a million years ago in which your hominid ancestors are gazing at their first campfire. Eyes wide, jaws slack, their faces probably lit upmuch like the 3,500 or so humanoids on Saturday who tried on Google Glass, a hands-free, voice-activated, wearable computer expected to be technology’s Next Big Thing.

“OK Glass, take a picture,” a woman commanded, her right eye fixed on a screen hanging in her peripheral vision. Her friend posed and smiled.

Seconds later, Glass complied. On the screen appeared the photo, which she could have later shared on social networks or in real time, using wi-fi or Bluetooth.

“There you are!” she exclaimed.

Durham, headquarters of American Underground, a network of business and tech entrepreneurs, was the first stop on the national Google Glass tour. Just 10 days earlier, Google had named American Underground one of seven technology hubs in the U.S. to receive access to the company’s financial support, products and mentorship.

The two events created a sense that Durham is at a tipping point, transforming from a gritty tobacco town to a trendy techopolis. Meanwhile, Glass, which is expected to be commercially available next year, could push society to its own tipping point.

We are becoming agents of “augmented reality.” Using a computer network to overlay information on the real world ostensibly enhances our experience, although it could be argued that mediating life through a screen instead diminishes it.

With cameras mounted on our head, we are literally embodying the surveillance state. Our friendsbut also law enforcement and the governmentcan live vicariously through us. It’s as if we’re the puppeteer traveling through the portal in Being John Malkovich but we don’t have to land next to the New Jersey Turnpike.

All day, the line to get into Bay 7 at the American Tobacco Campus was 150 people deep. Ranging from preteens to senior citizens, many who queued up to test-drive Glass spent the wait staring into their cellphones, unfazed when a passerby yelled, “You’re bringing civilization to its knees! Turn back!”

With Glass, enthused a corps of Google presentersurban 20-somethings in black Chuck Taylorsour necks will get a reprieve. Untethered from our cellphones, we can look up at the Glass screen and “still be in the moment,” Risa, a presenter, said.

Be In the Moment: It’s a catchy phrase, an aphorism you will find on a Zen website or a mindfulness tutorial on YouTube. But once we turn on the Glass, mentally there is no other moment except the full-color screen. Even as a shadow in our peripheral vision, it is an immersive environment where little else matters.

Sure, we can go about our day with Glass turned off. But it demands our attention. We can use it to text, to record, to ask questions, to chat on Google Hangout. Just as we have become dependent on our cellphones, we will become addicted to Glass. It’s virtual crack.

“OK Glass, record a video.”

With voice activationor if it’s too noisy for Glass to hear you, with a tap to the templeyou can record a concert in its entirety, noted Lisa, another Google presenter. (However, concert venues could ban Glass.)

Bootlegging is benign compared with surreptitiously recording people. Google has announced Glass won’t include any facial recognition software, and is banning developers from creating third-party apps for the device.

Even with an illuminated screen to indicate it’s recording, the video feature is Glass’ most nefarious applicationand potentially a good way to get punched in the face. (Your nose will break, but not Glass’ titanium frame.)

Google already faces several privacy lawsuits, including a recent class-action over its scanning of emails sent and received by Gmail account usersand, by extension, non-Gmail users they communicate with. Google computers then analyze email content to bombard users with advertising.

Google has responded by claiming Gmail users have “no presumption of privacy” in regard to electronic communications. That presumably extends to Glass, which knows what you’re viewinga restaurant menu, medications, a pair of shoesand for how long.

Third parties and Google could then target advertising to your Glass, which could become tantamount to a billboard that’s always in your rearview mirror. Google could also unleash its patented pay-per-gaze advertising, which charges advertisers based on the Glass wearer’s viewing habits of ads on billboards, in magazines and online.

The glassault on privacy extends beyond the wearer. While people in public have no expectation of privacy, in privately owned spaces, such as department stores, it’s reasonable (and probably naive) to think surveillance is to prevent theft, not to spy on you.

More troubling, though, is Glass’ potential function as a portal for government surveillance. The National Security Agency already monitors our email and phone communications; Glass enables NSA to put its eyes on the streetthrough ours.

“OK Glass, get directions to nearby coffee shops,” reads a Glass pamphlet.

Glass, make that nearby coffee shops that allow Glass.

Cocoa Cinnamon in Durham has taken a pre-emptive strike against Glass. A sign on the door prohibits people from wearing the device on the premises, making Glass as pernicious as smoking and guns, which are also forbidden. (You can order signs from the anti-Glass site

A friendly counterperson at Cocoa Cinnamon told me the no Glass policy was enacted so “people don’t have to worry about being recorded. This is a private, relaxed space.”

Many casinos, banks, strip clubs, schools and hospitals have also banned Glass. (This would presumbly apply to the 8,000 Glass Explorers nationwide, including 40 in North Carolina, who paid $1,500 for the privilege to beta test the device.)

Expect restrictions on Driving While Glassing, which undermines the navigation feature that appeals to many potential users. Instead of visually consulting a map on our phones or GPS devices, we can listen to Glass give us turn-by-turn directions.

Its “bone-conduction” technology doesn’t speak into our ear, said Risa, who spoke to my group, but is more “like a voice in your head.”

Nancy Torborg, 57, was trying on Glass over her prescription lenses and seemed at times to look at me with one eye. Although she is among the 150 million people in the U.S. who wear some type of corrective eyewear, she could still read the Glass screen. (Google is developing a prescription version of Glass.)

However, Torborg, a school librarian, said she is sensitive to Glass’ potential civil liberties issues: “I worry about privacy.”

Across the room, Alpha, 29, seemed less concerned about his own privacy than the perception of others. “Would people think I’m a threat to their privacy?” he said.

Asked to give his last name, he declined.