A couple of cases involving service provider immunity under the CDA (47 U.S.C. § 230(c)) came down within the past week. In Chicago Lawyers' Committee v. Craigslist, Inc. (N.D. Ill. Nov. 14, 2006), the court held that the CDA bars Craigslist from being held liable for publishing discriminatory housing ads in violation of the Fair Housing Act, although the court in dicta rejected the "essentially uniform body of case law" including Zeran v. America Online (4th Cir. 1997) that grants broad immunity to websites under § 230(c). In Barrett v. Rosenthal (Cal. Nov. 20, 2006), the court issued a much broader decision affirming broad immunity for service providers.
For more on these decisions, see commentary by Eric Goldman (also here), Susan Crawford (also here), Kurt Opsahl (also here), Eugene Volokh, Evan Brown, and Robert Ambrogi.