The price of being a celebrity, the pursuit fame and fortune. It's not fair, but that's the nature of the business.
I don't think there's ever a point in going too far, as far as paparazzi is concerned. They are willing to crash into celebrities' cars, assault their kids' nanny, tailgate them till an accident occurs. There's nothing they wouldn't do to take a good picture.
Aniston' suit would carry more weight had the photographer sold the pictures. There was a similar incident of an authorised video clip showing a topless Janet Jackson at the poolside. The clip made its way to the Internet, Jackson's lawyers took action, and the clip quickly disappeared.
So in a sense, it only goes too far when there's money involved, or lives being endangered.
Photos taken in public locale are public domain. Nobody, not even celebrities, can sue for that. California law is very lax towards these kinds of things. I'm sure it's a similar case in Florida, Scott, where the National Enquirer is based.

As long as the perpetrators don't lay a hand on the person, they can even go as far as to point a video camera under a woman's skirt and capture what she wears (or don't wear) underneath. Aside from moral outrage and/or threats of assault (on the perpetrators), it is not deemed a criminal act and not prosecutable in court.
The best way to deal with it is to avoid the spotlight (which some celebrities have done and in doing so better able to protect their private lives), stay away from 'hot spots', and move to places where such behaviour can be prosecuatable in court, like Wyoming, Idaho or Virginia. It also helps to not engage in high-profile/high-risk activities like drugs, partying, extra-marital affairs and such, which are magnets for paparazzi.
But I must confess I enjoy looking at the photos. So yeah, I don't feel all that sorry for them.