What exactly is considered bypassing DRM in the case of Beeper Mini, and what copyrighted content is the DRM protecting? This might be news, but the DMCA laws

What exactly is considered bypassing DRM in the case of Beeper Mini, and what copyrighted content is the DRM protecting? This might be news, but the DMCA laws don't allow you to restrict software which is compatible with your own, especially if the competitor never used your code.