Michael Buesch, lead developer of the Linux driver for Broadcom's wifi chipset (bcm43xx), stumbled across copied code in the OpenBSD's bcw driver earlier this week. The problem is that the bcm43xx linux driver uses a GPL license. OpenBSD inadvertently makes that linux code available to be used in a proprietary manner, by virtue of its BSD license (and not giving proper attribution where due).
The most difficult thing in the world is to know how to do a thing and to watch someone else doing it wrong, without commenting. -- T.H. White