Well, we have a law about electronic bulletin-boards. It's up to the one that runs such a blogg to remove posted material from other users that is abettal, persecution against ethnic groups, child pornography or if it's violating copyrights. If the owner of the bulletin-board doesn't remove it - he is the one committing the crime, even if it was somebody else that posted it. I guess this law is only used if the bulletin-board is hosted on a server in Sweden.