There was no way you could shoulder surf the combination. Even if you planted a camera the head of the person opening the safe would be in the way of the camera's sight line.
The banking example on the site actually implies designing an ATM specifically to take advantage of this feature. There are often people around you when you use an ATM.
Other products where security is an issue (special more-secure laptops?) could be designed this way as well. You wouldn't do banking with people watching, but if you needed the ability to do company work while, for example, spending a lot of time flying, it might be a net benefit.
We all would look at the limited viewing angle as a problem. Not enough people can see the TV, colour is bad, blah blah. But if we were to look at the problem in reverse - Too many people can see the screen from all angles, colour acuracy is not that important for all applications, and so on... we actually define a product that we can fit in the banking, HR, etc roles.
The next feat of genius was looking at what was causing the original problem and then leveraging it to create the new fuctional solution. Many just use the polar lenses, now you can just create a app that overlays invisible ink.
go to the demo page here:
look at your laptop screen from above and below (i.e., tilt or rock it) - not side to side.
More details here:
Turns out, the 'secret' text is coloured to blend in with a white background, but the page doesn't actually enforce a white background; my light-grey background doesn't provide enough contrast to read a novel, but it brings out the 'secret' text nicely.
I fought Samsung for false advertising using every method I could find and eventually they just gave me 2 24" IPS's and a 22" that can do 3D. The IPSs are really nice, but you can fry an egg on them they run so hot.
Using one of those shitty monitors if I get to the sweet spot where the text is invisible, if I move a hair up or down I can see the text :S
I wonder if that could be iterated further such that all of the screen is blurred from the sides (presumably by dynamically altering the "overlay" to cancel out each color of each pixel).
This would then make a great alternative to a privacy screen for use on planes, etc.