You are obviously missing the point but let me humor you:
When you access a bank you are publicly trading the information between you and the bank. That means that if somebody on your LAN sniff your cookies (and SSL wouldn't be used) you could use their account on their bank website.
So yeah, bank info is public as well.
You cannot use the internet and expect things to be completely private like you can't go in a bar get naked in the middle of the dance floor and expect nobody to notice it. (Ok, this is far fetched but still.. I thought this was funny :P)
That means that if somebody on your LAN sniff your cookies (and SSL wouldn't be used) you could use their account on their bank website.
But I use SSL when I connect to facebook. And its not the data facebook collects as it files over the wire that is being called into question here, it is the actions of Facebook once they have the data.
The point the parent post was driving at is: Is it OK for the bank to do anything they want with my personal data just because they (like facebook) happen to operate on the internet?
And my answer to that question is, if you give information about yourself to any service you have to expect them to do something eventually with it. Even if it's yours, it becomes theirs as well as soon as you upload it to the 3rd party.
what is the username and password to your online banking account?