I know I'm flogging this topic a bit but I have one more point to make. The using of the wrong words is bad enough but what really made me angry when I was in the US was people who couldn't conceive of anyone thinking differently to them. The fact that the original word existed before they came up with their brilliant idea to use it for something else doesn't even register.
"Whut? Y'all sayin' somewhere else can tell America whut tuh do? What are you? Some kinda Ayrab-commie-tehrist?"
Like this time I was in Vegas with a local and I got distracted by the flashing lights and almost walked into a telegraph pole. And I actually said "Whoa, I almost hit that telegraph pole." And he stares at the pole for a while, clearly wondering what I'm talking about, then he gets this big shit-eating grin and says to me like I'm about 5 years old (and not the brightest 5 year old in the kindergarten either) :
"Dude, we have this new invention called the telephone. We don't communicate by telegraph any more, this is a telephone pole."
There's no answering that while maintaining dignity so I said: "Shut up and get me to the pony express office. I gotta drop off this postcard before the rider leaves."