I was at a party in New York City earlier this year, and a conversation went like this:

Person: What do you do?
Me: I'm a computer programmer at Microsoft.
Person: <viciously> I hate you.

If Miss Manners didn't say so explicitly, I suspect she would nevertheless agree that snarling "I hate you" to somebody on first introduction is not exactly getting off on the right foot.

[Raymond is currently away; this message was pre-recorded.]