Slander is spoken word not written. The term you were looking for is libel, and even so it makes it pretty hard to prove someone is making a false statement when in many cases you can't prove it false for the same reasons it can't be proven true, particularly the share structure argument we see so frequently.
In any case people are getting banned and posts are being removed because they are directed at individual posters or groups of posters, rather than the points that person makes, often times containing personal attacks.
Its pretty simply actually, if you don't want your posts deleted or don't want to get banned, then keep your posts about SPNG and about the subject of a post rather than the poster who made it.
