Re: So, uhhhmm, why should I care?
At worst, he would crash the whole IFE system and nobody would be able to use it. But, yes, as long as it isn't connected to anything else, I see it as annoying, but not a real (inflight) security issue*. The IFE should be patched.
* Well, it might be a personal security issue for him, if he deprived everybody onboard of their entertainment...