Hitch, in your OP, you asked, “Should atheists stay non-violent? or reply aggressively?”

Question 1 - I think non-violence is the best choice for everyone until or unless self-protection or the protection of another from physical assault is at stake.

Question 2 - should ‘atheists’ reply aggressively? Reply to what? In other words, I think it’s situation dependent. Behaving or speaking aggressively as a matter of course (as SOP), I think, is ineffective, frequently shutting down any chance for a dialogue that leads to substantive learning.

Conversation is the single best learning device ever invented. I’ve heard so many folks who identify as atheist complain about aggressive theists who threaten fire and brimstone by replying angrily that the theist is stupid, insane, etc. The result is a yelling match that usually results only in raising the blood pressure of the participants.

I wonder how many folks who were once theist moved away from it because they were treated aggressively by someone with whom they disagreed.

It is easy for folks to complain about aggressive theists. Rightfully so. It seems less often that folks who identify as atheist will call onto the carpet another atheist who is on a verbal tear with a theist who is not behaving that way.