Google turns the light off

After switching my PC on and start the Internet I saw a black site with Google. Google wants to remember people that today in the evening between 8.00 pm and 8.05 pm (GMT+1) We all should switch the light off to save some energy and so save the environment.
The idea is not bad to get people to thing about their energy consumption and the environment but the question is if it is really good - because many electrical tools need more energy by turning on than they would need in 5 minutes running. And the next question is - what will happen if really thousands of people in a town will turn off the energy and after 5 minutes on at the same time?
Nobody knows.... we will know it - in about 6 hours.... I will let you know.