Philosophically speaking, Twitter is it amazing invention in that it allows for direct contact between executives, celebrities, and other public personalities to their fans and followers without having to expose something like a phone number or personal e-mail address. That makes it easier than ever for executives and other VIPs to communicate one-on-one with the public, which can be a great thing for branding and public relations.
Of course, if a free-flow of information back and forth between a single person in the world is the upside, then the downside lies in the fact that too many of us tweet without thinking.
In other words, once something has been shared, expressed, or posted on Twitter, then you can't really get it back. There are too many examples of public personalities trying to backtrack from something he tweeted to even count, but each of them carries an implicit warning: Twitter is a great marketing tool, but executives and business owners should be very careful about thinking before they share.
Don't assume that something you put on the Internet – and especially Twitter – is going to stay personal or confidential. Count on your tweets being read by everyone you know, and even the public or media. Doing so might be an overly-cautious step, but it will also allow you to take advantage of the best of Twitter without feeling the worst.