For politicians and celebreties twitter\facebook etc has become almost an essential tool of the trade, like a website is for a business.
It's how they publicise themselves, or 'get their message across'.
The trouble is, as you say, one hasty press of the submit button with that stuff and you're screwed.
Not being a celebrity or a politician, I'm happy in the knowledge that I shall never have anything to do with twitter. I shall never write a tweet, or read one either, unless it's rit's printed in a paper or something.
I've always thought it's complete bollx.