I think you mean invasion of privacy?
This can only be given if the person is in a place where they can expect a reasonable level of privacy. E.g. taking a photo of someone walking down the street is not an invasion of privacy (although it can amount to harrassment if done on a number of occasions and causes concern to the individual etc, but that is another case!) Using a big fat zoom and taking photos of someone who is in their secluded back garden or house can amount to an invasion of privacy, even if you are not trespassing to take the photo. Although it is not very clear cut an how to justify a reasonable level of privacy.
In the UK you can take photos of recogniseable people/faces and use them for your own commercial gain WITHOUT them having to sign a release form. This is not the case in a lot of countries though. A photographer can also take pictures of people's private property and use them for their own commercial gain so long as they are not trespassing to take the photo.