If you're not familiar, the way X11 works is comparable to "multiplayer notepad" for your pixels ("multiplayer MSPaint"?).

All your monitors are combined into a large canvas where every pixel can be written and read by any X11 client.

Screenshots (and screen sharing) could be silently performed with zero user feedback (or any good way to even detect when apps might be doing this maliciously, AFAIK).

This is one of the big "security implications" that motivated Wayland (and somewhat similarly, the Flatpak sandbox and the XDG Portal infrastructure that has by now outgrown it).

The infrastructure is already there, for 3rd party apps to request these abilities (with the user getting the choice of following through, or denying the request), e.g.:

- https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.fr...

- https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.fr...

Keep in mind that any action which doesn't require interactivity every time (e.g. restarting the screensharing of a previously-chosen window/display) could have "user gave permission" be remembered, but that seamless case still only applies to that combination (so that client can't peek at anything else than what it was offered).

Anyway, what the blog post is talking about is really just 3rd party apps that haven't been updated (and e.g. might already not function properly inside Flatpak).

> feature parity

If we are being honest, screenshots/screensharing was never a "feature" of X11, it was a big security hole abused as a feature.