"California's wiretapping law is a "two party consent law". California makes it a crime to record or eavesdrop on any confidential communication, including a private conversation or telephone call, without the consent of all parties to the conversation. The statute applies to "confidential communications" -- i.e., conversations in which one of the parties has an objectively reasonable expectation that no one is listening in or overhearing the conversation. See Flanagan v. Flanagan, 41 P.3d 575, 576-77, 578-82 (Cal. 2002). A California appellate court has ruled that this statute applies to the use of hidden video cameras to record conversations as well. See California v. Gibbons, 215 Cal. App. 3d 1204 (Cal Ct. App. 1989)."
Oops.