Ray-Ban Stories, Ray-Ban x Facebook, source: The Verge
EXPECT RESTRICTIONS to come IN AR
Privacy is one of the challenges when it comes to everyday Augmented Reality glasses (ARG), it involves both ARG users and people around them. We are still in the early days of adoption as ARG are still bulky and much used indoor, but the technology keep on developing and it's time privacy aspects of outdoor usage need to be taken into account. In my opinion, standardization should be made as a way to protect ARG users and people's privacy.
It's right to be worried
I try to be as optimistic as I can but the risk does exist for both ARG users and others involved. One drawback of ARG is that they can be easily used to violate others' privacy through the act of media recording, as it can be operated invisibly, thus ARG users themselves can be targeted as privacy violators even when they are not. In this post, I want to focus on camera usage for taking photos and videos, if you want to see a post on exam cheating, wait for me on that. ​​​​​​​
Should the operation be invisible? An indicator might help
At the time Google Glass was released 9 years ago, there were few reports of violent attack on Google Glass users on the street, the reason behind, according to some of the attackers, was the thought of their victims recording video without their consent. Normally, when the picture or video is taken from mobile phones or cameras, the sign of using the camera is usually visible, but the case is different using ARG since its user can record a video without objects' consent and recognition. 
My suggestion is an indication, it can be either sound or light indication or both. The indicator, for example, can be a LED light, which is on while recording video or taking pictures as showed in the figure 2, sound as indicator is less applicable but should be also considered. An indicator provides sign of camera usage, thus can be detected by others, this is also helpful for detecting in camera restricted area but there are still some drawbacks.

Figure 1: An example NReal mixed Reality Glasses with a LED indicator added

Location-based restrictions
Location-based rules and policies regarding camera usage can be found everywhere. In a courtroom or movie theatre for example, camera is strictly banned for copyright and privacy concerns, ARG, on the other hand, can be used to bypass these rules due to its invisible-to-others operation, media recording can be performed without anyone notices. 
For location-based restriction regarding ARG, it can be enforced by either banning the glasses or establishment of a digital restricted area, that automatically prohibits the use of camera when entering, this method works like a no-flight zone for drones that digitally restricted the pilot to take off within the area( more information can be found here). Manually detecting and banning glass users method is without much additional cost but only works well on the small area and easy to be bypassed, whether the digital method can be applied on a larger scale and can be automatically enforced, but it comes with a cost for implementation on both ARG manufacturers and the restricted area authorities, let's me explain!
On the ARG side, for the automatic restriction to work, common standards are required among manufacturers, these standards might include a set of definitions regarding hardwares/softwares deactivations defined in the operating system. On the restricted area authorities side, the indoor locating system need be installed so it can map the restricted area and advertise the data packet through wifi or Bluetooth to the ARG within the area for camera usage deactivation, these processes happens internally between the two systems and do not require actions from user. 
For example, when entering a movie theatre, marked as digital restricted area, the indoor positioning system of the movie theatre will send a packet to the ARG that require it to deactivate the camera recording, thus prevent the risk of copyright violations. Technical wise, this can be done using Bluetooth Low Energy or Ultra Wide Band indoor positioning to map the restricted area and advertise camera deactivation packets.

Figure 2: Camera restriction sign in the theatre

Expecting attempts to bypass on those restrictions
"For every lock, there is someone out there trying pick it or break in"
David Bernstein
Let be clear, I do not know who David Bernstein is without some Google search, but I do believe in what he said. I have suggested some ways to prevent bad acts regarding ARG usage, but there are maybe better ways that can be done, and also ways that can be used to bypass. For example, for indicator such as light, the most simple way to bypass is using colour tape to hide the light, to bypass digital restriction, on the other hand is more complicated to perform and might require advanced knowledge of the systems. There will be bypass attempts target on the both methods I have suggested, and its protection might be at risk but at the end of the day, a lock is better than no lock at all.
It's right to worry about ARG and its related privacy concerns, but I tend to believe the advantages of an appropriate ARG will overweight its drawbacks and standardisations might be the way to prevent bad acts.
Phuoc Trinh