Please stop attempting to have "private" conversations in public at a volume level where others can easily overhear you.
To be clear, I'm quite nice to people who deserve it, and to people who haven't shown anything either way (i.e. I am nice to strangers whose personalities I simply do not know). All I'm saying is that I feel no need to accommodate jerks. It's strange that society has conditioned us so strongly that such an obvious statement is seen as shocking.
I generally don't care if you're talking at the next table over and I can hear what you say, although I'm happy to be entertained by it if it's amusing. However, I think it's idiotic to be at that next table over and then be shocked, shocked that the information you're broadcasting is actually being received by other people.