Actor Alec Baldwin's been having a real up and down life recently - his career is hot due to his popular role on 30 Rock, and he's just married a woman who seems to have helped him turn his personal life and habits around. On the negative side, he's gotten into two well-publicized battles with paparazzi - consistent with conflict he has had with them for many years.
In one of the recent fights, Baldwin apparently got upset because paparazzi were blocking the street in front of his home waiting to photograph him, and when a neighbor complained to a photographer, she was cursed out by him. Baldwin interceded, and got the usual response that the pap had First Amendment rights to be on a public sidewalk to take photos of Baldwin.
The general rationales supporting paparazzi activity is that celebrities give up their right of privacy in exchange for their right of publicity, that celebrities have a public forum to discuss their unhappiness, and that the newsworthiness of obtaining photos of celebrities leaving Costco or Starbucks gives paparazzi the right to track and record the daily movements of their targets whenever they have the poor judgment to venture out into a public space, like a street.
This last point is usually framed as an argument that there is no reasonable expectation of privacy available to anyone in a public space. While stalking laws have been used to enforce celebrity rights to be free from stalkers entering their homes, or repeatedly calling or texting them, it takes a particularly egregious case to support a "distance injunction" preventing a photographer from being too close to a subject - see, e.g., the case of Jackie Kennedy Onassis versus Ron Galella, in which a court issued a stay away order directing him to stay 50 feet away from her and 75 feet away from her children.
While courts have repeatedly found that there is no right of privacy expectation in public space, this isn't really the point. The idea that your choice of occupation must be made at a cost of having your own personal space being constantly invaded, as well as that of your friends, family, and neighbors, just seems wrong to decent people. If privacy rights are not a valid means of addressing this, then we need to consider other remedies, perhaps sounding in tort for harassment, assault, or related offenses. Fine actors, politicians and others have been driven out of their chosen careers by this conduct. We as a society built on laws can do better than this, and we need to.