Though it attracts lots of media attention, Google Glass is really only a prototype with limited functionality. Along with a few other Android apps, it is very much a fledgling work-in-progress. It has been released mainly for app developers to tweak and make truly consumer-ready.
Google Glass consists of a heads-up display unit, with a headset clipped to a pair of spectacles. It is positioned at your right temple with a glass cube in front of your right eye. It also includes a camera and a data connection. The cube's focal length is about 2.5m, so it gives a projected image which appears to float in the air. It is, Google claims, "the equivalent of a 25 inch... screen from eight feet away".
A button on the headset operates the camera to take pictures or videos that can be synced with your Google+ account to be shared online with others.
Attaching a tiny camera, microphone and speaker to a pair of spectacles is not an original idea. But adding Internet connectivity makes invasions of privacy in plain view possible. (Glass has no connectivity per se, so you have to tether it to your smartphone by wireless or Bluetooth.)
Glass doesn't have a red LED to indicate that it is recording video, so you could be doing so at any time and no one could tell. In a public restroom, that should cause some concern.
Surreptitious video recording can invade privacy in non-voyeuristic ways as well, for example, a coach spying on his athletes to see if they are using steroids, or a private eye capturing videos of a target engaged in some crime.
Once the camera is turned on, Glass continually captures ambient video from the wearer's surroundings. That ambient video can then be stored, reviewed, organised and streamed or disseminated later. This is where privacy concerns come in.
There is a petition on the White House website calling for a ban on Glass until privacy concerns are addressed. Local women told RazorTV this week that they would certainly confront anyone secretly taking pictures of them in public. But can someone actually expect privacy these days when he or she is out there in public as a community member, consumer, employee or passer-by?
While the United States recognises a right to privacy, Singapore does not. But in both countries, there is no right to privacy in a public place.
The argument is that anyone entering a public place of social interactions and shared experiences takes it for granted there are people around, some of whom may be scrutinising him surreptitiously.
It is thus assumed that the individual concerned must have voluntarily waived his right of privacy (whether this is explicitly recognised in law or not).
So when Glass videos someone shopping at an Orchard Road mall at lunch time, it is not disclosing anything private. The camera does not lie, so there is no false portrayal or defamation of the person caught on video doing so.
Today, with smartphone cameras used in public so widely, many like to document their lives with quotidian images and videos which they share with friends and faceless others on the Internet.
So it might be argued that the reasonable person is unlikely to find the use of Glass in public to be highly offensive. After all, Glass is not concealed. Indeed, it is immediately obvious to others.
Moreover, it is argued, there is no discernible difference between casual observation of a person in public and catching him on video. So if he appears in public of his own free will, then his visage and his foibles, if any, should be fair game for any videographer.
Contrary to these seemingly obvious arguments, experts argue that there may be a basis for some privacy rights, even in public. In a 2001 journal article written when she was teaching law at the National University of Singapore, Ms Disa Sim, now a partner at Rajah & Tann, noted that a person who does something in public should not be assumed to be freely undertaking the risk of being caught on camera too.
It is arguable that consent should be separately necessary for that to be allowed, she wrote.
Second, privacy is not absolute in the sense that it is not necessarily something one has or doesn't have, she argued. Instead, there can be degrees of privacy.
I can think of an example where you visit me at my workplace but that should not mean you are free to access my ultrabook. So also in public: I know I will be seen out there but not necessarily examined closely by a multitude of strangers wearing Glass.
Third, being casually observed is quite different from being caught on camera, Ms Sim argued. The latter enables a larger audience to make out details that could have passed unnoticed, banal or otherwise.
To use another example: A man passionately embracing a woman who is not his wife might be comfortable with performing that fleeting act in public, but would probably object if someone captured an image of it to be shared with his family - and wife.
Fourth, one may dare to do something in public because the anonymity in public space affords one some cover to do so, Ms Sim suggested.
Say I can get in to a venereal disease clinic only by the front door. I take the risk of being seen because I assume that my anonymity in public will be a cloak to some extent as I dash in. But it doesn't mean that I also freely accept being closely scrutinised - and identified - doing so.
Finally, Ms Sim points out, not all public spaces are the same.
I may have freely assumed the risk of being video-recorded if I entered a public event at the Botanical Gardens where there would be TV camera crews, for example. Likewise if I am involved in a sordid sex case in court and I am caught exiting the Subordinate Courts at day's end.
But that may not be true if I am playing with my children on the beach or collecting my underwear at the laundrette. So privacy expectations in different public spaces could vary significantly.
Google must show why such arguments don't apply to Glass if it is to be accepted.