On May 13, 2015, the Iranian hacker Dr.3v1l of the hacker group Black_Devils B0ys successfully hacked and defaced the website for Saudi Arabia's General Authority of Civil Aviation. According to the hacker, the attack was in retaliation for the Saudi hacker RxR HaCker's defacing of the Iranian Ministry of Defense Website.
Source: Irancybernews.org, May 13, 2015.