I will freely admit to switching ON all the lights at home during Earth Hour. I was protesting a protest that I believe to be false and pointless.
False because the basic premise that humankind would be better off in a carbon-reduced society is unproven. Pointless because the exercise was introduced as a "fun" thing to do, having a candlelit dinner or, in warmer climes, a beach barbeque.
The organizers should have considered the idea of Earth Week or even Earth Month. But it would have been a complete failure for their purpose in that Mr and Mrs Joe Public would have soon begun to realize (possibly in the second hour) that this was not going to work.
No emergency room at the hospital. No street lights to ward off burglars. No office or factory come Monday morning. No telephone system. Etc.