Now in the example you chose, there is a different element in play, in that your camera is, ostensibly, for security and surveillance. I cannot speak to the specific laws of any state, but if surveillance is indeed the intent, I don't see it being particularly at issue for you to have the camera simply positioned somewhere.
It may be, however, that some states or municipalities have laws governing what areas may be observed by surveillance. For example, I cannot point a camera from across the street and at your bedroom window and claim that it is for surveillance on the side of my house. I don't want to be too anecdotal about that claim, but I was present for a neighborhood dispute with a similar situation in which one party was a lawyer and made some statements to that effect.
But back to wiretapping charges. It's best to simply know the laws in your state. In the State of Texas the recording a private conversation is legal as long as at least one party in the conversation is aware of it. You cannot record two random people in a private setting without their consent, but you can record your own conversation with someone, even if they are not aware of it.
[1] - http://www.boston.com/news/local/massachusetts/articles/2010...
Example: I put up a camera in front of my home that films the walk to the front door and of course it captures events transpiring on the sidewalk or street in front of my house. I'm not home, it is filming 24/7 automatically. A police officer stops a car in front of my house. Am I breaking the law? Which one?
May a police officer enter my property, climb a ladder, and hang a flag over my camera to prevent filming them performing their duty? Why? Why not?