Safe use of Web 2.0 and Facebook

Hello, I have questions for all of you!

I am teaching a semester long class called Computer Literacy. The class will meet every day for 55 minutes.

I believe that one of the most important topics to cover is "Safe Use of Web 2.0" both because of real threats and--perhaps more importantly--because of internet paranoia. One question is what should I cover? My initial list: Facebook, cell phones and texting, AIM. I think I will need to take a survey to get a sense of what is actually being used, but I'd love your thoughts.

I want the unit to be as real and specific as possible. In other words, I want to talk about Facebook and display actual Facebook profiles demonstrating problems as opposed to talking about "social networking" in the abstract. Of course, one of the problems with this is that the sites that most demand coverage are the sites that my district has decided to block. I intend to cache several Facebook pages, including my own, and display those. Does anyone have a simple and elegant solution for doing this within Firefox without much manual finagling? Many of the page downloading systems demand too much time. I guess, I can just take screenshots, but that is tricky when pages are bigger than one screen and require scrolling...

My attitude on Facebook, and on most web 2.0 content is that one should assume content will be visible publicly unless very trustworthy evidence can be presented to the contrary. What other precepts should underlie the unit? I was pointed at this by a Classroom 2.0 user: http://cybersmartcurriculum.org/. Does anyone have experience using their curriculum?

As an aside that I can't help thinking about...
In my personal life before becoming a teacher, I was happy to rely on security through obscurity. I don't have an identity that asks to be stolen--no money and no fame--and my professional life in software was completely unaffected by exposure to my relatively tame private life. Of course now that I am a teacher my perspective on privacy has changed. My realistic requirements for decorum sometimes chafe against my belief in free expression. What implications does web 2.0 have in this regard?