A user has had a bad experience installing a global theme on Plasma and lost personal data.
Global themes do not only change the look of Plasma, but also the behavior. To do this they run code, and this code can be faulty, as in the case mentioned above. The same goes for widgets and plasmoids.
We are calling on the community to help us locate and quarantine defective software by using the “Report” buttons available on each item in the KDE Store.
Please see this linked image to locate them.
Nevertheless, this will take time and resources. We recommend all users to be careful when installing and running software not provided directly by KDE or your distros.
And remember to report any faulty products you find!
What exactly do you expect users to do when they see “WARNING: what you are doing is unsafe” message? Cause the only outcome I can think of is that they won’t install themes at all.
As someone who works in infosec, that’d honestly be an ideal outcome. Because users don’t check their sources.
What would be better is if countermeasures such as not allowing that kind of code to be run by the theming engine and also code scanning on the repository with automatic takedowns on detection were put in place.