L' INTELLIGENCE CYBER par Jean-Paul Pinte

The theory goes that you have your “white hats” who are the good guys, your “black hats” who are the bad guys and somewhere in between – potentially swinging both ways – you’ve got your “grey hats”. Whilst the white hats are theoretically always on the side of good and walk a pretty straight line, the grey hats may step beyond that line into the murky territory that is more about breaking into things than what it is protecting things. Whilst they can actually be enormously useful at highlighting security shortcomings, they can also make quite a mess of things.

http://windowsitpro.com/troy-hunts-security-sense/security-sense-paradox-grey-hat-hackers