When IBM filtered those unpatched security flaws by severity, however, Google came out as the least likely to patch critical security bugs in its software that would allow a hacker to completely hijack a target system, leaving 33% of those high severity flaws unpatched over the first half of the year.

FORBES: Connect

But the ICO said the fine reflected the severity of the security lapse, adding that it was among the most serious it had ever seen.

BBC: Sony fined over 'preventable' PlayStation data hack

To demonstrate the potential severity of these security vulnerabilities, the researchers tracked the Skype accounts of about 20 volunteers as well as 10, 000 random users over a two-week period, using techniques that neither harmed nor disrupted the service, utilized any requests for which the service was not designed nor interfered with users.

FORBES: Unfixed Skype Bug Reveals Users' Locations, Downloads