Seahorse wrote:
managed to scrawl the following bloodstained message

1. Don't cross post.

Why shouldn't one cross post?

Because it's rude. See below...

http://www.netlingo.com/right.cfm?term=cross%20post

Problem is, those who know very little tend to make anectodal
generalizations.

It's like a tourist visiting a country and being told, at a certain
occasion, that crossing his legs when sitting is rude. He comes home
and tells everybody he knows his newfound wisdom: "When you go there,
never cross your legs. It's very rude. They'll chop them off!" It
becomes a myth (*).

There are certain circumstances where it may be considered rude and
others where it's not and anything in between. Also, no country is a
homogenous blob. There are certain to be people or regions that don't
care. Our tourist is simply trying to replace good judgement with bad
generalization. Never (!) do that.

(*) Only, in our case, it's worse because there's a positive feedback
cycle: Usenet newbies who have come to erroneously believe that all
cross posting is rude will themselves start shouting bloody murder
when they see a cross-post. Thus, the myth ends up being reality.