From our parent: I used to work in the antivirus industry, and, as I recall, anything that even hinted at a history of hacking or virus-writing would lead to instant dismissal and black-listing (from pretty much the entire computer security industry). I imagine that the same prohibition would now apply to former government employees also.

They used the world "hacking", which I took to mean any form of hacking. We'd need the parent to respond to which one was meant, of course; but if it means any sort of hacking, from xbox modding to submitting bug and exploit reports to Google (which, how do you know if there's an exploit without trying to find it?), then hacking would include all of those people, including the people who you define as "ethical hackers".

If you're a known, aggressive and clearly unreformed cyber-saboteur, then it's pretty much a given that you shouldn't be hired to an anti-virus company since you probably are in there to commit insider attacks (I can't know for sure, I'm not in your brain) and it's reasonable to not hire you; however, if you're a tinkerer and inspector of things and dismantler of technology, then you would know how systems work and where issues are and could even be an asset, especially if you're very good at it. Depending on the author, both of those people could be seen as 'hackers'.

A number of notable, convicted hackers have done additional work (whether employment or successful entrepreneurship or both) in the computer industry (in security-related or other subfields) after conviction. Kevin Mitnick, Julian Assange -- long before WikiLeaks -- and YC's cofounder Robert Tappan Morris are among the more notable examples.

Having a spouse, kids, and a nice house in a nice neighbourhood makes any kind of anti-social behaviour that much harder to justify from a purely pragmatic, never mind ethical point of view.

I.e. young men often have nothing much to lose and act accordingly.