A researcher who specializes in the security of commercial airplanes was barred from a United Airlines flight after he tweeted a joke about hacking a key communications system of the plane. Tripwires Director of IT Security and Risk Strategy, Tim Erlin, provided the following comments: One of the most obvious cyber security challenges in the aviation industry is the increasing sophistication of attacks, and the participation of so called nation-state actors. It is a challenge for information security professionals to defend against nation-state attackers.”]