EgyptAir security guards differ in several respects from the undercover air marshals who travel on American airlines. Three EgyptAir security officials said the threatening graffiti, which appeared about two years ago, had been the work of aviation workers at Cairo Airport. EgyptAir has fired employees for their political leanings, stepped up crew searches and added extra unarmed in-flight security guards. Prevost noted that despite extensive efforts to ensure security, workers can sometimes be threatened into co-operating with criminals. Colleagues described the Egyptian security guards who died in Thursday’s crash — Walid Ouda, Mohammed Farag and Mahmoud el Sayed — as professionals who had exhibited no signs of unusual behavior.

Source: thestar May 21, 2016 21:18 UTC