Assumption 1: Facebook is globally sensitive.
This post was sparked by this article Japanese with common last name Yoda denied Facebook account. While I understand how Facebook, being an American invention, could let slip the occasional unawareness of things non-American, I cannot imagine how anyone who had any vague sense of Japan could have so decisively decide, without any Googling even, on the inauthenticity of a name like Yoda!
Assumption 2: Facebook is absolutely private.
The Internet creates the illusion of privacy. Just because blogging in my bedroom "feels" private, it does not make it so. Private stuff on Facebook is not really private. Especially when you have many "friends" so as to make the idea of privacy moot. Or if you don't set the privacy settings appropriately.
Assumption 3: What is yours is still yours when posted on Facebook. No, what you post may not be yours in practice.
I am still surprised that many people think of their Facebook page as "theirs". Anything you post on the Internet, including Facebook, you will lose control of. Simple as that. I may well own the copyright to my writing on the Internet. But there is nothing to stop others from simply stealing them and claiming ownership of them.
Assumption 4: Facebook is a reliable comms channel.
It never ceases to me that people rely on one single channel of communications like Facebook, in this day and age where it takes no effort and cost to set up Gmail, Hotmail and Skype accounts. When Ms Keep's Facebook account was turned off (see this Sydney Morning Herald article), she had no other means of engaging with the people on her Facebook account. I can only hope she had other means of contacting these people. Why would anyone rely on a single channel of communications for their livelihood? Facebook is not a phone company.
Assumption 5: Facebook is backed-up.
Ms Keep imparts another valuable lesson: "she never thought to back up data she had stored on the site such as her photos and contacts." If you even half-heartedly surf the net, you will quickly come across sad stories of people losing their data to hardware, software, and service failures. And yet, time and time again, some excuse will be trotted out about why there were no backups. Facebook make no promises for the absolute safekeeping of your data. If they did, they'd be stupid.
Assumption 6: Facebook is the Internet.
Although most people probably get online just to use Facebook, and therefore understandably confuse the two, it does not make Facebook the Internet. Facebook is still a walled garden owned by a single corporation.