Glenn Mangham imprisoned despite claiming he just wanted to help Facebook by pointing out vulnerabilities.
A 26-year-old British student, who stole sensitive information from Facebook's internal network, has been jailed for eight months.
Facebook spent $200,000 (£126,400) dealing with Mangham's crime, which triggered a "concerted, time-consuming and costly investigation" by the FBI and British law enforcement, Mr Patel said.
"This was not just a bit of harmless experimentation - you accessed the very heart of the system of an international business of massive size," Judge Allister McCreath wrote in his verdict.
"This was not just fiddling about in the business records of some tiny business of no great importance and you acquired a great deal of sensitive and confidential information to which you were simply not entitled... Potentially what you did could have been utterly disastrous to Facebook."
- Technews