The answer to the Facebook privacy scandal

is surely not to put up anything you don't want to share with the entire world?
I have been thinking about this rather a lot recently. One person I know removed herself from Facebook last month. I am not at all sure that solves the problem as she sees it. Her information is still there - and I am quite certain that the internet spies still have ways of accessing anything she does on line.  I have no doubt at all that, as I write this, internet spies are following every key stroke.
Paranoid? Perhaps - but with good cause.
I tried a little experiment the other day to show Ms W what happens. I accessed a site I was not interested in but I thought might throw up some particularly vigorous results. I was as certain as I could be that the site itself was harmless but I was also certain that it would be looking for business.
Yes. 
I accessed the site from advertising on the Guardian website and the advertising magically appeared on Facebook.  Ms W eyed it off and said, "That's why I will keep on doing my email stuff on my Dad's address."
She writes to a friend in England, another in Scotland and one in Italy this way. The emails she sends are rare.
I pointed out that when she researches things for school she is still  giving away information. We agreed there isn't much she can do about that. It doesn't really matter anyway because I am sure she isn't accessing anything illegal or undesirable. 
Her father was one of those, as she puts it, "fancy phones" that are really a mini-computer. I suspect he is cautious about what he sends and receives. He has a second such phone for work purposes and he is probably even more cautious about the information he sends and receives on that. 
I have an old, very old "pre-dinosaur" phone and anyone accessing that would be deeply disappointed. I've made about three calls in five years. 
Internet banking? I have a post office related debit card. The rule is you can't have more than a thousand dollars in it - and I have never had that amount anyway. If the internet spies are interested in the second hand books, the yarn, the craft supplies, the Senior Cat's new phone and a few other oddities I have bought over the years that's fine.  I don't pay utility bills that way. I haven't booked tickets of any sort.
I do a little bit of Facebook socialising and I post a link to the blog there and on Twitter. I try to be very careful about what I say in both places. 
The only time I have pulled something down was when I asked the Guardian to remove a post I had written. There was nothing wrong with the post itself but there were some vicious, racist comments in response to someone else's comment on my post. The Guardian's guardians should have removed those comments but failed to do so. It is something they need to work on - and a lesson to me. Don't comment there.
It would probably be wiser not to comment anywhere or at any time. It would probably be wiser not to use the internet at all but there is an increasing demand for us all to do so. Go "paper-free" and get your bank statements on line - and much more.
I am not going to stop using the internet or remove myself from Facebook or... I am just going to have to go on reminding myself to be careful and not post anything I might regret. 
Will I regret writing this?