Privacy is a perception.
In the coming weeks/months, you'll hear a lot of griping about how there's no privacy in Gmail, how various proposed laws will take away from your freedom, and possibly some other issues will arise out of the increasing rhetoric that culminates in November.
Whether or not any of it is true is beside the point. Pundits treat "privacy" as an all or nothing thing. It doesn't work that way. If you're over a certain age, hundreds if not thousands of people are intimate with various details of your life Examples include: doctors, lawyers, law enforcement, your spouse/SI, your pet's vet, your bank, numerous insurance companies, your neighbors, public utiiities, your employer. Need I go on?
Privacy in public places is even more of a perceived issue. It is dependant on the degree of conformity you are willing to submit to. A very bad example is from the movie "The Matrix". How many of you remember the blonde in the red dress? Okay, now describe the last person to pass between her and the camera. (Hint: they were wearing dark business clothes and sensible shoes.)
You can drive to work every day, at or near the speed limit, no one will take notice of you. Do twenty five miles an hour over or under the speed limit and everyone else near you will take notice, especially if their job involves traffic control.
Your e-mail can get inspected (and normally is) numerous times, for malicious code, content, legitimacy. It leaves a trail on whatever mail server/handler it passes through. Some of those systems may keep copies of the entire message. Now people are up in arms about a service whose computers attach targeted advertisements to messages and makes your mail folder searchable (note: they've always been searchable in some form or other).
This country has numerous laws which protect your privacy. However, just like tax laws, there are hundreds of exceptions to those laws, most of which do not require notifying you of their use. For the majority of our online life, it translates into the phrase "expectation of privacy".
That "expectation of privacy" depends on our "perception of privacy". Most of us don't know that our ISP's keep records of what we do online and/or periodically scan for TOS compliance. Many of us don't care. A good portion of those that do know and do care consider that "invasion" as a protection.
A good portion relates to how unique you believe yourself to be and how worried you are that the rest of the world may take an interest in the minute details of your "private" life. How paranoid are you? And yes, just because you're paranoid doesn't mean that "they" aren't out to get you.
Brad Templeton (of the EFF) and John Battelle have quite a few good points, for and against, GMail. Personally, I think the proposed California legislation to ban GMail is idiotic for the same reason that I think most of the other arguments are silly: no one is going to force you to use the service.
Another point is that many of the other web-mail services already do, in some form or another, what Google is proposing to do (see Mr. Templeton's article).
I haven't tied the above together all that well but I think it's the start of a good argument. What do you think?
(Note to you TCC alumni: this fall's class involves Cyberlaw and you'll need to be able to argue either side or both sides of the argument.)