Truth is offensive, it's why bored people who play video games all the fucking day think so highly of video games. Any potential evidence that it could be harmful, like television, and they get on the defensive, as if you're attacking them themselves.
Absolutely beautiful. People will react to abrupt changes with hostility and resentment because it jeopardizes their easygoing way of life. "WHAT? YOU'RE TELLING ME I SHOULD GO DONATE BLOOD OR DO VOLUNTEER WORK? THAT'S RETARDED, WHAT A WASTE OF TIME". In this, the person would rather sit on their ass all day and let their TV entertain their useless brain instead of getting up and putting out some effort to create a positive change in something. I think one of the biggest problems nowadays is that everybody has lost their community, or desire to have one. Working together creates positive change, whereas working seperately makes one person rely on himself for support, which eventually leads to stress and hatred. Completing a project or something with other members is much more beneficial to everyone, and can be a great social activity.
'Spergin - You're on your way to getting it, but you're only seeing the outer symptoms.
What I see here in what you described is an inability of people to transcend and use ego to serve themselves and others. They live to serve ego instead.
Often the truth is most offensive when you introduce to a person a piece of information that is contrary to what they believe. Or what they might like to believe. Usually people will call you a dick or demand that you "shut up". I wouldn't let this be a deterrent though, because if you say nothing at all, the stupidity will continue and things continually worse.
This may have to do with the way you present the information. You probably already know how to, but I like to double-check:
Don't present it with the attitude of "AHA I HAVE EVIDENCE THAT GOES AGAINST YOUR WAY OF LIFE!!!" if you don't want them to react to the information negatively. You need to feign neutrality and ask questions as in the Socratic method.
Otherwise neither of you learn anything, and you only piss people off. Don't act too dumb, but ask the questions of a genuinely-interested person in a way that will expose the flaws of their own thoughts while sharing this information with them. Practice makes perfect.
In the context of some offensive/truthful information -- If they're confused or mad, be on their side:
"Oh, yeah, I thought Obama would be a promising president as well, but more and more people think he's just all hype. Bells and whistles. They might be right. Hmm.. it's worth looking into."
Let them poke holes in their own beliefs, and patch them up with something that works. You may gain new insights in your own beliefs and thoughts as well. This is more helpful to people that are inclined to seek knowledge though.
Too many people like to assert their beliefs a little zealously, and as a result, push people away. You have to be like an alluring flower to whom bees flock of their own accord and delight.