I can't speak about what the censorship is like in the European countries, but, I can talk about what it's like here in America; that being primarily the silly after affects of a Protestant past (and an Evangelical uprising) and a healthy dose of the conclusion that media has powerful negative influence with no sufficient evidence.
The censorship of words is more rediculous than anything else, last time I checked, any American movie which says "fuck" once is instantly PG-13, if the movie says "fuck" more than once it is instantly rated R. Why is this? Because of a silly unsubstantiated fear that "bad" words will have a negative influence. The idea of "bad" words is rediculous to start with, the only reason they're bad is because someone at some point in history arbitrarily decided that they were bad. There are some exceptions of course, racially and sexually derogatory terms, as well as some others are bad for a reason, but there's no reason that "fuck" should be a bad word.
Bigger issues here in America are sex and violence. Many Americans don't even realize that there is a rating called NC-17 (this is the modern equivalent of the X rating) the reason for this is that with exception to porn movies, the NC-17 rating is an absolute death sentance for any movie. The problem, of course, is that this DOES ultimately restrict artistic expression. I am a big fan of horror movies, and I know this genre is frequently restricted in what it is able to show because of the ratings system. Some are fighting it, of course, even some names some of you might recognize. Eli Roth (Hostel), James Wan (Saw), Rob Zombie (The Devils Rejects), and Quentin Tarantino (So many famous movies I can't even begin to list them off) are part of a group that calls themselves the 'splat pack,' and actively campaign against the NC-17 rating. It would be nice to see more people jump on board with the hope of creating freer artistic expression.