not sure if this is still the case on kde 6 or if this is a distro thing, but at least in kubuntu 22 and iirc 24 too certain files when right-clicked have sharing options, alongside one that immediately uploads the file to imgur without warning or confirmations and only then gives you the delete link in a dismissible notification, this can be disabled with the purpose configuration files, an example turning off the imgur integration is in the readme under "Disallowing plugins": https://api.kde.org/frameworks/purpose/html/index.html