The foremost proof of which (even more so that road rage) is the office coffee pot. The fact that so many feel that they can take the last of the coffee and then blithely walk away is evidence that we've fallen on un-civil times.
My employer is kind enough to provide three different kinds of coffee, and on more than one occasion I've walked up to find all three karafes completely empty. I rage, swear, cry to the heavens, and then set about making three pots of coffee, as is only fitting and civic-minded.
I understand that in some circles it's seen as stigmatizing and degrading to have to "make the coffee" at the office, since someone is just supposed to attend to it, but come on people, the 50's are long gone, and administrative assistents have no more duty to make coffee than do each and every one of us.
So be civil, thoughtful, respectful of others, and make the @#(@*$% coffee! The 20 seconds it takes are worth the feeling of pride you can take in not being one of those non-coffee making so-and-sos.