In-flight entertainment system is barely connected to the important parts of the airplane, if at all.
Hackers Remotely Kill a Boeing during Flight - With Me in It
http://www.wired.com/2015/04/hackers-commandeer-new-planes-p...
And even so if the screen in-front of every passenger did then started to spew a bunch of boot logs and generally behave strangely. I beet people would become quite scared.