Where is Common Decency?

Over the span of my short life of 29 years, I have seen human decency fall lower than I thought it could.  Respect for other people’s space, beliefs, health, privacy, property, and rights (to name a few) is almost a myth. 
Just 10 years ago, when someone noticed that a person didn’t cuss in their everyday speech, the person who cussed would normally keep their cussing down to a minimum when around that person out of respect.  People who smoked wouldn’t smoke around children (of course, after scientists discovered that it was bad for our health).  When a person said they were having trouble at home, the boss wouldn’t ask for all the gritty details.  Drivers didn’t drive on your property without expressed permission or damage your things just for the fun of it.  I remember living in an area where the neighborhood kids could ride bikes and play in the street without worrying about anything but letting people pass when they were driving down the road.
IMHO, I’m positive that the major reason for this trend is the fact that parents don’t go to church, or bring their kids to church any longer.  Church is an important place for a child to get involved and learn how to treat others.  I guess the real problem is that people today don’t have a relationship with God… I mean, how can they if they aren’t taught what they need to learn on a regular basis.  There are many children out there who want to know about God, and want direction/correction in their lives, but they’re not getting it.  We have children coming to our church without their parents that yearn for basic discipline.
I know what you’re saying… “yeah, right… what kid wants discipline?”  Every kid has it built into their DNA to look for authority.  The problem is that most of them never find it, and decide it doesn’t exist at a young age.  Just a few years later, they don’t look for or respect authority.  If they don’t believe in an authority, why on earth would they respect anyone else?
I’m bringing this up because someone I know is not being treated right.  The argument actually applies to more than a few people I know, but I’m upset about one in particular right now.  What is the best course of action for dealing with someone who is being rude, hurtful, and disrespectful to someone else you know?  I am currently questioning how to react.