PR Week reports on what’s surely the tip of the iceburg – the hijacking registration of a major corporate brand by an imposter “employee”.

Twitter, the social flavor of the week site that’s attracted a huge following and is now closely followed by corporate America – just ask Comcast – began issuing tweets from ExxonMobil, registered on their site by someone called Janet.

Imagine the surprise when the corporate cats at the real ExxonMobil found out after the brandjacking was first reported in the Houston Chronicle a few weeks ago. A quick petition to Twitter and control of the account name reverted to the real owner, no damage done for now. But it doesn’t take a genius to figure out how bad the mischief could have been.

The lesson’s probably this: if you’ve got a brand worth protecting, it’s your responsibility to perform the due diligence required for policing the internet and making sure everything said in your name is, in fact, something you meant to say.