I think it depends on the person who says it, what the content is and most importantly what mood the reader is in.
Best friends can have a fallen out over the way something is read, hence the every growing need for smilies.
On an open fourm on the internet its all how things are perceived, and if your friends with someone your more likely to let things slide but when someone who you dont get along with post something you dont like your more likely to bite.
Humour all depends on the person.
I like dark, sick and twisted jokes but there is a fine line from funny to down right sick and just cause i laugh at those kind of jokes i dont post them on the boards as i understand not everyone would like them.