Riginslinger -- there's a good link up there to a piece about people who used to be called "Fire bugs". Arsonist is a better word I reckon. Less cute.
We're getting better at identifying causes of fires now. Amazingly deliberatly lit fires are common. Often it's people ignoring fire bans but it may also be arsonists. The increased mobility of everyone has meant that arsonists can be lighting a series of fires along a bush track and get out of the way and off home before they're noticed. The methods are very simple.

Causes under the heading of stupid, ignorant, momentary lapse, or unable-to-understand-and-unsupervised are:
Tools that throw off sparks, camp fires, cigarette butts thrown from cars, people burning off, little kids with matches and firelighters, power mowers -- and many more.
Causes like these are known to be responsible for bushfires in the past. On Saturday the grass fire that put us on alert was the result of a burn-off. The warnings were there, what can I say. *&&%%$###** !!! Workmen with power tools started one of the Ash Wednesday fires. In the 1970s terrible fires in the town where I lived were started by little kids with Mummy's cigarette lighter.

The pressure has eased somewhat. We can't yet say the word controlled but the weather continues to be kinder.
Cheers, Joy