WARNING: Global themes and widgets created by 3rd party developers for Plasma can and will run arbitrary code. You are encouraged to exercise extreme caution when using these products.

A user has had a bad experience installing a global theme on Plasma and lost personal data.

https://www.reddit.com/r/kde/comments/1bixmbx/do_not_install_global_themes_some_wipe_out_all/

Global themes 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.

https://store.kde.org

Please see the attached image to locate them.