Being from California, especially growing up in the San Francisco Bay Area Coastal Range, Fire safety is ingrained in me. One of my youngest memories is the of the Oakland Berkeley Firestorm of 1991 - I clearly remember (even though I was like 4) a giant smoke cloud extinguishing the sun from my parents house. Dozens were killed and thousands of homes destroyed.
That fire was started accidentally according to most reports. An RC aircraft over an urban or forested area can easily cause a devastating fire if the conditions are right.
We all have to be careful with our hobbies and remember that human life, property safety, and ecosystem safety come first.