CafePress removes "Blue" products

CafePress has blocked the products based on Blue, and that shop has been closed pending whatever this is about. What their robots emailed me:

We recently learned that your CafePress account contains material which may not be in compliance with our policies. Specifically, we prohibit the display or sale of products which depict the use of "hard core" drugs, content which may infringe the rights of a third party including copyrights and trademarks, and material which is generally offensive or in bad taste. Accordingly, we have set the content that we believe to be questionable to "pending status" which disables said content from being displayed in your shop or purchased. For more information on acceptable and prohibited content, please review our Content Usage Policy....

Let's see... there's nothing about "hard core" drugs, or drugs at all.

Although I did my best to make sure I used only public-domain images, there is a possibility that something I used was copyright, without my knowing it.

There certainly couldn't be anything in that patriotic, anti-tyranny content that anyone could find objectionable, except tyrants and haters.

So, must be the copyright. @@