Any suggestions as to how to report this?
Leo The Lion explained the methodology.
PM [Personal Message] myself or another Moderator and any issues can be looked into.
It is assumed that any works uploaded belong to the uploader, or, if another's work is used then appropriate consent is sought/received/included, or the image, etc is freely available for public re-use.
This is also the 'terms of use' connected with uploading works here on Wincustomize.com
https://www.wincustomize.com/about.aspx
See "The Rules" .... #1
Don't confuse 'free for personal use' as 'free to upload/redistribute', as the latter is what artists' copyright is all about....