The Home of the Underdogs basically host abandonware, software that is not longer commercially available. Problem is, under current copyright law, what they are doing is infringing on the rights of those who didn’t explicitly allow them to do this. So they are technically in violation of copyright. They don’t want to have anything on their site that they shouldn’t have, so they provide a means to request them to remove it. If your game ended up on their site, and you don’t want them to distribute it, even if you aren’t selling it anymore, you can ask them to remove the download.
Some people completely understand and respect what The Underdogs are doing: archiving our video game history. Archive.org does a similar service for the world wide web and now television. Technically, backing up the entire known world wide web infringes on a LOT of copyrights. In this case, though, I think it is providing a great service. Libraries do the same. Anyone can get a copy of any book or film or audio recording and watch/read/listen for free. The author still owns the copyright, but the public gets to use the works for free. Isn’t that just legalized piracy?
Yet there are people who are adament about how “wrong” it is. Yes, The Underdogs should probably have asked for permission first instead of going ahead and waiting for the requests for removal afterwards. But don’t throw out the baby with the bathwater. They have a lot of games available WITH the permission of the copyright owner. That’s perfectly legal and not piracy.
For your own personal knowledge and for a better treatment on the discussion of copyright in this day and age, please read Lawrence Lessig’s Free Culture. It discusses how piracy actually created whole industries: airplanes, Hollywood, recording industry, etc. It also discusses how copyright used to be limited and these days the powers of the copyright owners have expanded, sometimes to the detriment of society.
Don’t get me wrong: I don’t believe that software piracy is always and necessarily good. I just don’t believe that every infringement is necessarily wrong or evil. I like those silly Flash animation montages and the fan fiction and the ability to look at the state of the world wide web at any point in time. Some people seem to think that all of those things are not just illegal (I don’t debate that), but that they are also wrong.