First off it doesn't matter if the service is free, it's the ethics behind it. It's your content, you made it. All it took was a few strokes of the keyboard for your content to disappear, and no reason given behind it except just to say that the RIAA owns it.
second I believe the law here need to be changed. If you file a infringement against someone then you should have to say what is "exactly infringing. With the way the law is set up now. It can be abused very easy. All they have to say (or lawyers say) as just in this case and many more like it is "hey remove it it is violating my music copyright". Then up steps a content provider like Google that has to remove the source or else they can get sued too. This is not fair to the public when you leave the public in the dark about what the RIAA is yelling foul over, or anyone else that decides they don't "like your content". Be open about what's going on and if you decide that certain content is infringing, then tell the blogger or website owner exactly what is infringing.
This is the most biggest thing I have against the copyright laws. Anyone can cry foul, and service providers quiver and jump to remove the so called content. I have heard of cases of other people having to remove content, or they had content removed by their provider, and all they was told is "you were violating a copyright, and I don't have to tell you what content". "You just need to know what page it is on." So the owner of the content has to remove the whole page of content because they have no idea what exactly on that page is infringing. In most cases it is just one file, or one URL causing the problem.
Come on people this is the most stupid of laws, and excuses. This needs to be changed. Give the public a break here the only ones that are benefiting from this law are the ones that decide they want to infringe upon you because they don't like your content. Who knows they may be after a monetary gain too. You could be a rival that they need too squash. What ever the case there is not enough responsible disclosure. If you have proof, then I want to see it. Not asking for too much right?