When Britain's domestic intelligence agency decided to recruit from the hacker community, for Cyber War tasks, they duly found about fifty suitable candidates. The new employees had to pass the screening process (background investigation and lengthy interviews), and sign the documents obliging them to comply with the Official Secrets Act (under pain of severe penalties). The latter item means they cannot discuss their new job with anyone outside of MI5 (and many inside MI5 who do not have a "need to know.")
MI5, like many corporations and intel agencies, have found that the largely self-taught recreational (and occasionally criminal) hackers have lots of useful skills that cannot be found in university trained software engineers. The MI5 hackers have quickly proved their worth, playing key roles in several counter-terrorism cases. One interesting aspect of all this is that most of the fifty new hires (or their families) were from Asia (mainly India, Pakistan and China).