It would be an interesting project for someone studying psychology, to try to work out what motivates these idiots. What do they hope to achieve by wrecking or defacing? Are they waiting (hoping?) for someone to be killed?
The underlying cause of the Craigieburn collision, as I understand it, was a vandalised departure signal. Probably "fun" to do at the time, but with absolutely no comprehension of the consequences which could (and did) flow on.
It's the same sort of motivation that leads people to join ANY sort of a club; they want acceptance and friendship with the main group of other mini-terrorists.
Many of these people are not children by any measure of the stick; we are talking about 30-something and in some cases even 40-something men who really, at this developmental stage of their lives, should be finding something better to do that trying to destroy the rail system or 'tag' things. There was the famous prosecution of two guys who called themselves 'Stan' and 'Bonez' a few years ago (occasionally you still see their tags around Melbourne) and I was astonished to see in the media that they were actually sad-looking balding middle-aged men - for some reason you always expect to see pimply teens but no - they're even more tragic as human beings than you can possibly imagine. Kinda sad really, like when you see middle-aged men still skate-boarding down the street with their caps on backwards... you're not that rebellious 20 year-old any more mate, let it go!
As a regular network user I find there's nothing more annoying than disruptions caused by someone wreaking the train you're supposed to be catching. Do these people actually use trains? Because if they did they would find it just as annoying as I do. The smashing of equipment and deliberate disabling of safety measures is also a very disturbing development; how long before they actually kill someone in this way?