Twitter - embrace or not - just be careful

I've been following the story about 'PR guru' James Andrews in the States who rather naively posted a comment about a city on Twitter, incurring the wrath of one of his companies top clients. For those of you that haven't seen it, Andrews was on his way to a meeting at Fed Ex's corporate headquarters in Memphis, when he Tweeted his hatred for the city. One alert Fed Ex employee stumbled on it and retorted with a rather sniffy response, cc'ing in a number of senior Fed Ex employees.
Andrews claims to be a social media expert, but I have to admit that he can't be that savvy if he didn't realise that - out of the near 1000 followers he has on Twitter - one of them might be from Fed Ex.
Yet another example of how companies and individuals need to watch what they say online.
Follow the rule - if you wouldn't say it to their face don't say it online.