Copyright ©2013 NPR. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.

AUDIE CORNISH, HOST:

From NPR News, this is ALL THINGS CONSIDERED. I'm Audie Cornish.

MELISSA BLOCK, HOST:

And I'm Melissa Block. Google Glass has generated lots of excitement, but also plenty of anxiety. It's a head-mounted computer equipped with a smart camera and the worry is it will erode our privacy. Google has responded by trying to make it obvious to people around these devices when they're being used. But as NPR's Steven Henn reports, hackers are reengineering Glass, passing some of that anxiety onto Google.

STEVEN HENN, BYLINE: So I'm sitting at Philz Coffee in Palo Alto, California, and this kid who looks like he should still be in high school is sitting across from me. He's wearing Google Glass and as I stare into the device's cyborg eye, I'm waiting for its tiny screen to light up. I'm waiting for a signal that Google Glass has recognized my face.

STEPHEN BALABAN: No matter what they say about the, you know, in the terms of service, you can run face recognition on this device. And it's been very difficult for Google to, I think, stop it, if people want to.

HENN: Google Glass isn't supposed to be able to do facial recognition but Stephen Balaban has hacked it.

BALABAN: Essentially what I am building is an alternative operating system that runs on Glass but is not controlled by Google.

HENN: Balaban wants to make it possible to do all sorts of things with Glass that Google's designers didn't have in mind. And he's one of a couple thousand coders and developers who got their hands on a pair of these high tech glasses this spring.

BALABAN: Google likes to think that they have control over how people use the technology that they create, but it's a Pandora's Box, right? Once you've opened it, it's very hard to say you have to use the technology in this very specific way.

HENN: Over the last few months, coders and hackers, like Balaban, has put Google in an awkward spot. The company needs to embrace their creative talents if it hopes to build a software ecosystem for Google Glass that's compelling and actually attractive to real customers. But at the same time, Google wants to try to reign in uses of Glass that could creep out or freak out the public.

So when Balaban first announced he had built a facial recognition app for Glass, Google quickly banned it.

BALABAN: I'd be lying if I said I didn't expect it.

HENN: The terms of service for Google Glass are much more restrictive than most other Google products. Still, developers are doing all sorts of things today with Glass that weren't built into the original design. Michael DiGiovanni created Winky, a program that lets someone wearing Google Glass take a photo with a wink of an eye. He says it's not for spying on people, really.

MICHAEL DIGIOVANNI: So I took a picture of a big sandwich that I had both hands on, hand a mouthful and I went to take a picture. A huge human need met. I mean, we've been waiting for how long to take the first person point of view shot of eating your own sandwich.

HENN: Marc Rogers is a principal security researcher at Lookout. He realized he could hijack Glass if he could trick someone into taking a picture of a malicious QR code. That's a kind of square-shaped bar code.

MARC ROGERS: The user wouldn't see anything at all. The user would take a photograph and then go on their merry way. Whereas what I would see is the user takes the photograph, the Glass would connect to my access point. My access point would tell me that they're connected and then it would give me some options as do I want to watch all their connections? Do I want to send an attack? Anything I wanted to do.

HENN: This hack would let Rogers turn on Google Glass' camera or send text messages or...

ROGERS: Read emails. You can put spyware on that will tell you what's going on. But the good thing is, that's not going to be the case because we found this vulnerability and fixed it.

HENN: Rogers disclosed the problem to Google and he says in less than two weeks, Google patched it. Today, Marc Rogers has nothing but praise for how Google responded to his hack.

THAD STARNER: That's the great service our explorers are doing for us.

HENN: Thad Starner is a professor of computer science at Georgia Tech and a manager at Google Glass. He says putting Google Glass into the hands of all these hackers and coders might look messy from the outside, but...

STARNER: They're actually teaching us what these issues are and how we can address them.

HENN: Starner's convinced, sharing Google Glass now with a wide variety of people should make the product safer and help Google understand how these wearable computers could ultimately fit into our world. Steven Henn, NPR News, Silicon Valley.

Copyright © 2013 NPR. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to NPR. This transcript is provided for personal, noncommercial use only, pursuant to our Terms of Use. Any other use requires NPR's prior permission. Visit our permissions page for further information.

NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.