The Electronic Frontier Foundation’s “Stupid Patent of the Month” for December isn’t owned by a sketchy shell company, but rather the Microsoft Corporation. The selection, published yesterday, is the first time the EFF has picked a design patent as the SPOTM. The blog post seeks to highlight some of the problems with those lesser-known cousins to standard “utility” patents, especially the damages that can result.

The chosen patent (PDF), numbered D554,140, would seem to be one of those things that’s so simple it raises some basic philosophical questions about the patent system. That’s because it’s just a slider, in the bottom-right corner of a window, with a plus sign at one end and a minus sign at the other. That’s it.

The patent was highlighted earlier on the blog of Sarah Burstein, a law professor at the University of Oklahoma who studies design patents and uses her blog to highlight some… interesting… examples. Many companies are getting design patents for things that are clearly functional in nature, like a Socket Wrench Tooth, or a rock dust blower, or even—really—a Quaker Oats granola bar.