Well, not just from the ACM, but also from people involved in the Ke-Sen Huang and ACM Publications situation.

• ACM SIGGRAPH membership also gives you access to just about all computer graphics papers in the ACM Digital Library. This I knew already, but found that others haven’t realized it. Any conference sponsored by SIGGRAPH is available, from what I can tell, e.g. I3D. I noticed a few weeks ago that the SIGGRAPH 2009  Posters were not accessible to me through this benefit; the ACM fixed this problem when I reported it.
• Deep linking, where one site links directly to content on another site, is not illegal. The EFF notes that deep linking has not yet been found to be illegal by the courts. However, linking to sites providing infringing (illegal) copies of a work for download is contributory infringement.
• “Sweat of the brow” compilations, such as the white pages of phone books, are not copyright. There is no original expression involved, so the Supreme Court ruled such are not protected. Paula Samuelson’s article in the Communications of the ACM (Google Scholar hits here) is a fascinating overview. Titles are not copyright. Elements such as the order in a Table of Contents are in a gray area, from what I can see. The ordering and grouping of the articles into sessions may be copyright protected – the courts have not ruled, as far as I know. Changing that order on an external web page would then not be copyright, since it would be a different “original” expression. Alphabetized or numerical ordering is not copyright protected.
• You do not need to enforce your copyright to maintain it, unlike a trademark. You can ignore an infringement and not lose your rights. So the argument that a copyright must be protected now in order to preserve it in the future is incorrect.