[xiaoma]

Considering how even non-personal information becomes identifiable in aggregate, this is a feature that any social site with a conscience should have. Otherwise, the risk to privacy is both impossible to gauge and continuously growing.

[jacquesm]

Or, alternatively you could simply think about the consequences of what you write before you write it.

ANY words you write on the internet or even in email start to have a life of their own right after you hit that 'reply' button. If you're the kind of person that would not stand by their words even years later then you probably shouldn't be clicking that button.

It saves others work down the line, and it saves you embarrassment.

[xiaoma]

I think you've missed the point I was making. The consequences are unknowable at the point of writing. The ability to search, organize and analyze data has grown and will continue to grow.

Online practices that were downright conservative in 1997 would expose personal details today. Similarly, what is safe now, likely won't be in the future as data from even more sources gets correlated.

"ANY words you write on the internet or even in email start to have a life of their own right after you hit that 'reply' button. If you're the kind of person that would not stand by their words even years later then you probably shouldn't be clicking that button."

This idea is ridiculous. People can't be expected to never change their minds and email users clearly have an expectation of privacy. Perhaps a few odd characters would happily "stand by their words" and share their email histories with the world, but the vast majority of us would not.

[jacquesm]

You have it backwards :)

Because you can not know the consequences at the time of writing you have to think ahead and not write stuff that you think you might regret in the future.

If wishes were horses then beggars would ride, you can wish for a way to undo stuff you said in the past but in practice it will only get harder to do that in the future.

More and more frequently the second you hit 'submit' your content is syndicated all over the globe. I pose that it is impossible to even know who copied down your words and where and when they'll pop up in the future, you should write with that in mind.

The law is a decade behind reality, it has never been any other way with technology. You may be legally in the right and you may have certain expectations but that will not make much difference.

Witness Jimmy Wales trying to wipe out the fact that he owned a porn site, in his profile it says (on wikipedia no less) euphemistically that 'bomis targeted males', but everywhere else ( http://www.wired.com/culture/lifestyle/news/2005/12/69880 ) for instance it is clearly visible that it was.

The facts stand by themselves, no amount of handwringing or wishing is going to make that any different.

If you don't want to be confronted with your own words in the future, don't write them and if you don't want to be confronted with your own actions in the future, don't do them.

There is no undo button on email to begin with, and no, you can't have a reasonable expectation of privacy there because you are sending your words to someone else.

Who can then choose to make your words public.