Kind of like when I first dragged a window across multiple monitors in the 90s. We are so used to content being stuck in artificial containers that it's kind of crazy when it transcends them.
This is a privacy leak. I have a 24" screen, and I don't keep the browser window maximized because it would be too big. I presume other people do to, and I'm pretty sure most have a preferred size and position.
Allowing a site to execute JS in your browser is equal to trusting them, like it or not, and browser vendors are definitely in the business of adding new APIs rather than reducing attack surfaces.
[1]: https://wiki.mozilla.org/Fingerprinting
[2]: https://github.com/Valve/fingerprintjs2
[3]: http://noc.to/
Back in the 90's, Microsoft and Netscape were all too happy to give JS developers the world with almost no regard for security consequences.
We've spent the last 20 years trying to fix their mistakes.
Web developers have always pushed for more access to information about the user and their environment. Browser and tool developers are happy to provide that access. There's always some use case that sounds reasonable, but you're right that it's just a security issue waiting to happen.
These holes are also being talked about in the new Wayland display server on Linux. Warping a mouse pointer, color picking, knowing your apps place on the desktop are all security violations. They are being very careful with that stuff because it's an insecure free for all with X.
Every time I upload an attachment to gmail or a picture to facebook, I wonder how secure things are. Those seem to require user action, but do they really?
I'm torn. On the one hand I understand the privacy implications; on the other hand, if you'd want to be serious about those, you'd have to get rid of JavaScript and half of CSS. Every interesting feature can be turned into a privacy/security violation; how far are we willing to go in removing them?
I know the quip about how in IT paranoia is not a sickness but a job requirement, but damn it...
As for web developers pushing for more information. No surprises there, its so they can more precisely fine tune the layout of the "app" (notice how they refer to what used to be called a site with a term that used to denote something running locally).
That it also can be used to fingerprint the computer, and by extension the user, is a side effect, not a goal.
Personally I don't care either, just thought you might want to know!
It seems like the child windows are 'special', perhaps the web page can obtain the relative coordinates of these child panels?
I don't think the method you're describing exists. If you want child coordinates relative to parent coordinates, you would use both the parent and child's absolute coordinates.
edit: I found the original site that I linked to this. Courtesy of archive.org: http://web.archive.org/web/20120214090814/http://blog.insicd...
The NeWS window system let you reshape the entire framebuffer to any orientation or clipping, as well as individual windows and sub-windows, in the late 1980's.
Why shouldn't I be able to lay down on my side next to a laptop and read a web page off the screen sideways, or adjust the rotation of the window to match the inclination of my pillow?
The other thing I want the window manager to support (which NeWS couldn't do since PostScript only supports 2D affine transforms) is estimating my head position relative to the screen, and projecting the window in perspective so it looks rectangular from an oblique viewing angle, so I can watch a movie on an extra screen off to the side.
If you could rotate windows around on the screen, Browser Ball should be able to use the laptop accelerometer to detect the true direction of gravity, and bounce the ball accordingly as you turned the windows and the laptop itself around.
Unfortunately Apple stopped putting accelerometers in laptops with SSD drives, since they were only used to retract the heads when falling.
You can do a lot of fun things by modeling and tracking the positions of multiple people's heads and multiple devices in augmented reality! Here are two people using two tablets, two laptops, and a desktop computer together with Pantomime: [1]
This is really scary to you? I get that you can do fingerprints, and honestly there's a LOT more than just browser window position/size in them, but "really scary"?
Maybe we need to stop exaggerating on this sort of stuff if we want people to take us seriously.
This tester uses it I believe: https://panopticlick.eff.org/
Maybe it only recognizes American addresses or something, but I don't know any of those.
edit: Ok I got it working by putting in Amsterdam, which happens to be a city and not an address.