My response:
Also, a recording, such as our writer asks about, is also controlled by the location of where the recording is being made. A determination of a recording's legal viability would certainly rest upon a person's "expectation of privacy," e.g., was the recording made in a public setting like at a park, or in a private area like a bedroom, or an office.
The Federal eavesdropping statute (18 USCA §§ 2510-2520, above) prohibits the admission in evidence of such communications and depends on whether the participants had a "reasonable expectation of privacy." Confidentiality is determined by an objective standard - - i.e., whether the complaining party had a reasonable expectation of privacy, not whether the party subjectively thought the communication was confidential. [People v. Wyrick (1978) 77 Cal.App.3d 903, 909, 144 Cal.Rptr. 38, 42; O'Laskey v. Sortino (1990) 224 Cal.App.3d 241, 247, 273 Cal.Rptr. 674, 677; Simtel Communications v. NBC, Inc., supra, 71 Cal.App.4th at 1080, 84 Cal.Rptr.2d at 337]
As another example, a conversation is "confidential" within the meaning of the California Invasion of Privacy Act (Ca Penal § 632) "if a party to that conversation has an objectively reasonable expectation that the conversation is not being recorded or overheard." [Flanagan v. Flanagan (2002) 27 Cal.4th 766, 768, 117 Cal.Rptr.2d 574, 575 (emphasis added) - - immaterial that the content of the conversation is expected to be communicated to a third party]
IAAL