- Libreoffice is still open, you want to reboot, the reboot deletes the document (maybe)
- You have any Text document open
- Your browser has an open form or post, where the website would block the tab from closing
What happens is, that this is ignored by the OS (at least on KDE) and you “are allowed to delete your data”. I see how this fits into the Linux idea of some people, but I think having an opt-out poweroff-block of this kind would be really great.
Do you know what would be required to do this? Is this purely a KDE thing?