The whole DRM thing seems to be a big scam. It doesn't stop piracy, but puts lots of restrictions onto users:

• You can't play legally purchased content on any device you have
• You are forced to use Windows only
• In many cases you can't play legally purchased content after re-installing an OS, system crash, system upgrade,...

Even large companies like Yahoo can leave their business without caring about customers. And there were much more smaller companies that died leaving people with unplayble content they have paid for.

Unfortunately you can't remove DRM before getting working licenses. So if you can't re-acquire them, you can't make your files DRM free. The biggest problem is that people realize it when it is too late.

What you can do?

• Spread the word about DRM removal software
  Tell your friends about your story. Tell them to remove DRM from all their DRM protected content, inclusing music, movies, TV shows, TV episodes, educational videos, ebooks,...
  e-mail your friends, contact them via Facebook and other social networking web-sites, create forum and blog posts.
  
• Vote against DRM protected content. Use services that offer DRM-free music, video,... Or at least remove DRM protection after getting any DRM protected content.
• Do not use any Yahoo services