Nah, it's just nutjobs, genuine pyromaniacs. Also the link with firefighters tends to be the other way around, people become firefighters because they like to light fires, they don't start lighting fires because they're firefighters (In most cases), because that way they have a legitimate reason to be close to the fires,and admire their own handywork.
Also discarded cigarretts don't tend to start fires from what I know, they just don't have the required heat to start a fire unless you're really unlucky with where they land however they let that rumour grow because that way people dont get ideas on how to be a copycat - in the same way that the media depics sliting your wrists across rather than down the arm. I think there have been a couple of cases were a cigarette would be taped to a match so that when the ciggarette burned low enough it would light the match, which is powerful enough to light up the dry grass.
Acouple of updates as of last night
181 dead (but still with pleanty of unsearched buildings)
over 1800 houses destroyed
aproximatly 7000 people left homeless
more than $100 million (aud) has so far been donated
no one can really guess how many head of stock were killed as a resault, or how much damage was done to properties (ie. fences, sheds ect) or the toll on wildlife.