I like that you specified from "educated" people. It's true, I really don't mind so much when uneducated people make such mistakes.
I usually assume that most atheists are educated and think that people who's first tongue is english should be relatively free of base grammatical mistakes. My schooling was in French, and francophones are much more anal about grammer than anglos are, which is why I notice these things even in English.
The most abused words I see on T|A and A|N are effect and affect. Their misuse drives me absolutely nuts. And worst, when I bring it up, people consistently hide behind "it was a typo"! Hiding their true lack of understanding of the distinction. :)