Vatican correspondent Edward Pentin reports that it was the Secretary of the 2014 Synod, Cardinal Lorenzo Baldisseri, who blocked the distribution of the pro-marriage book Remaining in the Truth of Christ: Marriage and Communion in the Catholic Church when it was mailed to each of the Synod fathers. The book contains chapters defending Church teaching written by Cardinal Burke, Cardinal Brandmüller, and Prefect of the Congregation of the Doctrine of the Faith Cardinal Müller, among others. Baldisseri was reportedly "furious" when he discovered that copies of the book had been mailed to each of the Synod fathers, and intercepted them. The books are believed to have been destroyed.
See also Dr. Ed Peters, "It was worse than a crime -- it was a blunder" (In the Light of the Law, February 26, 2015):
There are credible reports that Lorenzo Cardinal Baldisseri, head of the secretariat for the Synod of Bishops, ordered the confiscation of pro-marriage materials legally mailed to synod participants last October. In addition to whatever international and/or Vatican City State laws might have been violated thereby, and besides the possibility of the violation of Canon 1389 (abuse of ecclesiastical office), this action, if indeed it was taken by ranking prelate, offends at a level that will, I suggest, haunt Church staffers for years to come. Read more >>