John Connor was trained by his mother to fight against Skynet and the Terminators. But in the future described in Terminator 4, aka terminator Salvation, things aren’t exactly like John Connor may have imagined: Skynet is much more vicious and nasty than expected and the evil computer is coming with some new friends:

Terminator Salvation Pictures

(Click on a picture to enlarge it.)

I doubt we would be Luddites enough today to smash our computers in order to save Mankind from such a fate… So let’s hope that if such a tragedy ever happened, some savior like John in Terminator 4 will rise from the remnants of Mankind! The machines shall not win: Mankind must prevail!
:-)