"Reasonable expectation of privacy" is refers to whether you are performing something in public or not. I can take a video of you standing in Main Street shouting about Hell opening up and devouring us all, because you don't have a "reasonable expectation of privacy."
However, Wikipedia [1] implies this is not civil, but in regards to the government's view of privacy to you, not yours to the government, and is highly unlikely to supersede areas where filming is expressly forbidden, and which is indicated to you when entering that area.
That's not true for police officers in two party notification states; I'm not sure whether this applies to private citizens or not.
In Illinois and other two party notification states, you can't record audio of police officers in public places [1]. Video is fine, but since all video cameras record audio, it's a bit of a Catch-22. People get arrested all the time in two party notification states for video taping law enforcement and it's because of the audio function of their device.
However, Wikipedia [1] implies this is not civil, but in regards to the government's view of privacy to you, not yours to the government, and is highly unlikely to supersede areas where filming is expressly forbidden, and which is indicated to you when entering that area.
[1] http://en.wikipedia.org/wiki/Reasonable_expectation_of_priva...