Re Grab's 5. I think my newserver (the free x-privat.net) filters most of the spam out - once in a while I do see a reply to what was obviously spam that I haven't seen. In general, on the occasions I do see spam, what I find is:

usenet: usualy ignored.
web sites: posts telling the mods it should be deleted, "how dare you post this here" posts, etc.

for me, that does demonstrate the differences between user expectation, etc.