I've seen people increasingly using "amen" as a way to respond to a post on a mailing list, and I'm afraid it worries me. Do you see the problem in the following dialogue?
Person A. I think X is true.
Person B. No, you are wrong, Y is true
Person C. Amen.
Person C clearly agrees with B. There's no problem with that, but 'amen' just seems to be way too categorical as a way to say that. It feels like they're saying, "Person A, you're completely wrong, and not only that, I'm going to invoke religion to make sure you see that".
Perhaps person C could have just said "Yes, I think that Y is true also".
Would have been kinder to person A, wouldn't it?
(And who was that over there suggesting that I've recently been person A? Never...:-) )