Not sure where this fits.

SUMMARY
When I close my laptop lid, the machine suspends. When I open it, all my windows are visible with potentially sensitive information for a second or so before the screen lock kicks in.

STEPS TO REPRODUCE
1. Turn on the computer
2. Do something
3. Close the lid
4. Wait for the machine to suspend
5. Open the lid
6. Observe sensitive data


OBSERVED RESULT
The whole screen is visible for > 500ms before the lock screen kicks in. Someone not privileged to see that information could view some of that information, or if they've observed the effect a few times they could be prepared with a mobile phone or camera.

EXPECTED RESULT
The screen should be cleared (or overlaid with a black window) before the machine suspends, so that it's still clear inbetween resume and screen lock. I don't know if it's possible but it would be a good addition. This is not a new behaviour, so it's not practical to list all the versions of KDE with which this behaviour could be observed.