I don't see how it's hypocritical. Europe has all sorts of restrictions on free speech - think "hate speech" laws carried to an extreme - and, while I don't agree with the principle of that kind of law, everybody certainly has a right to use them.
Furthermore, "silence gives consent," that is, if Christians say nothing, this is taken as assent and an admission of the truth of the Da Vinci Code (which is actually a set of crazy old-style anti-Catholicism and New Age gnosticism).
I agree with that... but the Church's anger about this book and movie is way out of proportion to what the book really claims. There must be a million books published a year that makes claims about Jesus and the Roman Cathlic Church and its teachings. The Da Vinci code in comparison is very mild and very tame. I think the Church is in an uproar because the book makes a "somewhat credible" story and so many Catholics started to have doubts as to what the truth is.
The Church is the only institute in the world that could put this issue to bed. It has at its disposal the Vatican Archives that is filled with documentation and proof about the early beginnings of the Church. That is what the story line contends, that the early Church hid the truth about Mary and Jesus, right?
The Church has done this to "some" degree but the only thing most people read are stories like this. I would be interested in the Church producing some more interesting documentaries that show that Dan Brown's claims are wrong, instead of asking its followers to SUE. To me, that is just whitewashing the issue and well... that makes people just a tad more suspicious.
Only for simple-minded people... but then again you know those church people, they'll believe anything.