Some of licensing companies are bankrupt but their copyright is still in effect, so there is no owning company to complain. Some are just doing other things and don't want to spend the money to pursue what they see as an annoying niche market. Some are actively protecting their work but it's a big ass market and the vendors are out of jurisdiction. China, for example, doesn't exactly do a lot of copyright enforcement. You can note where a lot of these come from. Trying to stop every moody peice of code being sold on the web, or even amazon for that matter, is like trying to stop the wind with your fingers.