I can’t put it better than Bruce Schneier, commenting on a Los Angeles Times op-ed by Dennis Gilbert. People just aren’t rational about risk. They over react to some risks, and under react to others.
This has big implications for risk management, especially in risk identification and risk assessment.

More importantly, though, it affects how both we and those that govern us respond to global warming and terrorism.

We can’t just ignore the environmental impact of IT. If, as some hope, the Stern review is going to raise the profile of environmental issues, and lead to actual changes in business behaviour, then IT won’t be exempt.

We hear about leaving TVs on stand-by; PCs are just as bad.

Workers who leave their PCs on overnight are causing spiralling electricity bills and extended greenhouse damage to the environment.

…

The report found that workers did not turn off their PCs for five main reasons:

• They couldn’t be bothered (17.5 percent)
• No-one else in their office did (10 percent)
• Because it’s unimportant (10 percent)
• They forget (8 percent)
• They are afraid of losing their work (1.8 percent)

Well, you should save your work before you leave for the evening anyway.