Think of the most inappropriate e-mail you have ever composed. Remember the personal slights, the flirtatious asides and any outbreaks of expletives it contained.
Now think about how you would feel if that e-mail became public property, zinging around the office and the world.
Imagine the avalanche of prurience it would excite. Imagine trying to explain the blunder to your boss or significant other. Any attempt at damage limitation would be useless. In the wake of your sacking or divorce you would have lots of time alone to rue the day that Gaudin Ray Tomlinson invented electronic mail in 1971.
Do not assume all this could never happen to you because misdirecting an e-mail is easily done. Witness the recent case of United States corporate high-flier Mary Callahan who received an e-mail from a suitor, Tripp Murray, asking her out.
Meaning to forward the message to a friend, she prefaced it with these touching comments: 'Here is the e-mail I received from the new guy I met last week. Since we have not slept together, he will of course be trying to impress me and will, therefore, do anything I ask. Unlike John, who fell asleep during sex last night.'
So far, so foul. The e-mail made the transition from private malice to public menace when, in a gut-wrenching gaffe, she clicked the Reply button on her e-mail tool bar instead of forward. Her declaration was thus duly exposed to Mr Murray.
Peeved at being treated as a potential cash cow by a woman who could easily pay her own way, Mr Murray then spread the message. This e-mail became so huge it is now cited as a classic example of the Swire Effect, named after the infamous Claire Swire. In 2000 Ms Swire, who worked at a London dotcom marketing firm, sent her City lawyer boyfriend Bradley Chait an e-mail about the nutritional and cosmetic value of his bodily fluids. Triumphant about his conquest and her flattery, Mr Chait shared the exchange with some of his cronies, who in turn forwarded it to other acquaintances, thus unleashing the dialogue on the Internet.