secure financial systems that have been hacked. To see IT guys believing that a system is unhackable is frightening with it's complacency. Do you remember stuxnet?
There is somewhat a bit of a difference between aircraft systems and financial systems. Financial systems are not safety critical, you won't kill anyone if someone gets into a bank account.... so the ultimate design goals are very different.
And a difference between aircraft systems and stuxnet. You only need to go read up a bit on stuxnet to realise how "special" it was for many reasons (i.e. highly likely to be a well funded, "western" government project with specific targets in mind that they had evidently done much research on before). A
LOT of money and manpower went into stuxnet .... more than any tewwowist organisation could ever dream of !
I'm not saying aircraft systems are invincible, I'm just saying its utterly ludicrous to say someone can get 100% remote control over an aircraft, even more so in a manner that the flight crew can't overrule. The chance of an aircraft being hit by a meteorite is far more likely !