File:Blocked-background.png

Summary
This file is highly derivative of an image originally found on Wikipedia. It has now been changed to the point that the uploading editor (CzechOut) asserts it to be a novel work. The original file was either licensed under the CC-BY-SA 3.0, or flatly in the public domain. This version, believed different enough that CzechOut claims authorship, is now released under the CC-BY-SA 3.0 license.