It is no big secret that the RIAA hates people who use music in any fashion they don't approve of. They opposed personal media players, they opposed digital downloads and in the past they have opposed ripping your own CDs. As a matter of fact, they still oppose it. As a recent court case is demonstrating, the RIAA is willing to attack people who rip their own music, claiming that making mp3s from your own CDs is “unauthorized”.
Whether or not someone chooses to share that music, it shouldn't be up to the RIAA, or anyone for that matter, to tell you what you can and cannot do with a CD. It goes to show how archaic that organization has become, and how out of touch with reality they are. Apple has rebuilt their empire largely in part to people dumping CDs, Microsoft builds tools to do such right into their OS and there is a never-ending list of programs and suites intended to make such operations easy.
While they may have other grounds with which to attack these particular people on, relying on “ripping music is stealing” is a shot in the dark.