Forgive me if this is the wrong list.
Inkscape is an Open Source authoring program used by some Wikipedians to create SVG files. The author of http://en.wikipedia.org/wiki/Image:M1_Abrams-TUSK.svg placed one such image in the public domain. On examining the image, I found a non-public-domain texture called "Sand". Fortunately, the texture is under Creative Commons Attribution 2.5 . It has an "inkscape:stockid" attribute, so I'm assuming it is a built-in stock image of Inkscape.
It is possible that Inkscape is not informing image authors that their stock textures have a license. Those authors then dedicate the entire image to the public domain on Wikimedia, and do not note the licensing of the contained texture.
Recommended action: parse Wikimedia SVG files to detect <pattern> tags, see how many have this problem, fix information pages to indicate licensing of the textures, delete inappropriately licensed content if necessary.
Thanks
Bruce