I don’t usually do product reviews, in fact I have been asked a few times to accept a free product in return for a review and have turned them all down. This is just such an outré product that I have decided to write a review, despite not being approached by the company and having no connection. The product is the 3M Privacy Filter Gold. Here is one I was given at InfoSec, on my MacBook:
You’ll probably notice that the screen has some somewhat unsightly plastic tabs around the edge. They are holding in the main feature of this product, which is the thing giving the screen that slightly coppery colour. It’s actually a sheet of plastic which I assume is etched with a blazed diffraction grating, because at more acute viewing angles it makes the screen look like this:
OK, so you can still see the plastic tabs, but now it’s hard to make out the text. And that’s the goal of the privacy filter gold: it’s to stop shoulder surfers. By reducing the usable viewing angle of your screen. Hold on a moment, while I count the number of times I’ve been told about a business or government agency that leaked sensitive data through shoulder surfing.
And the number of times I’ve heard (or discovered, through risk analysis) that it’s an important risk for an organisation to address? About the same. OK, so this product is distinctive, and gimmicky, and evidently does what it’s designed to do. But I don’t see the problem that led to this product being developed. It might be useful if you want to browse porn in Starbucks or goof off on Facebook while you’re at work, except that someone stood behind you can still see the screen. OK, you could browse porn while sat on the London Underground – except you won’t be able to get a network signal.
If anti-shoulder-surfing is important to you, you may want to bear these issues into account. When used in strong sunlight, the privacy filter gold makes the screen look like this (note: availability of handsome security expert holding iPhone is strictly limited):
The MacBook isn’t great in strong sunlight anyway, but with the filter over the top it becomes positively unusable. All of that dust is actually on the filter (although it was fresh out of its packaging when the picture was taken), and causing additional scatterings through its grating leading to a “gold dust” effect on the screen. And yes, the characters “3M GPF13.3W” are indeed etched into the filter at the top-right, near that thing that yes, is indeed a notch you can put your finger in for extracting the filter from the plastic tabs.
That’s one issue, the other is price. Retail price for these filters is around £50, varying slightly depending on screen size. I’m really not sure that’s a price worth paying considering that I have no idea what the benefit of the filter will be.