Number 5: Light brings safety. There are safer ways to make a statement and raise awareness than to create a controlled time when thieves and rapists know they will be harder to spot.
Number 4: Everyone buys LCD monitors now, and LCD monitors work by placing the LCD sheet between an always-on backlight and your eye, so black screen backgrounds burn more energy, not less, than light backgrounds. Such poor symbolism only discredits everything you write, because it suggests a lack of forethought and research.
Number 3: The energy spent raising awareness about Earth Hour just might cancel out the energy saved that hour.
Number 2: One hour out of 168 in a week, 720 in a month, and 8760 in a year will not make a significant dent in your energy use. Less so when battery-powered gadgets are used during that hour, as then the energy is only shifted, not reduced. It's even less when people merely postpone activities until after the hour.
And the Number 1 reason is...
The amount listed on your electricity bill is only a fraction of the energy used to support your lifestyle. Do you buy imported goods, especially gadgets, that travel internationally? Do you buy food from a supermarket, or anything else transported by truck? Do you drive? Do you shop at stores which violate all the 'principles' of Earth Hour by blasting heat or air conditioning all day long, using continuous bright lighting, including external signage? What about the factories and farms where everything you wear, eat, or use is manufactured or grown?
Reducing energy use is a fundamental lifestyle change, not a light dimmer in the kitchen. Earth Hour only heightens awareness of how superficial the commitment is from the proponents of global warming. Get off of the Internet, as all the servers, routers, switches, backup power supplies, air-conditioned data centers, and rare earth metal-consuming manufacturing processes are far too costly to justify using them for playing on Facebook, Twitter, and MyBO.com.