The idiot liberal (yeah, I know..redundant) "leaders" of all the European countries should know that if they allow unrestricted immigration half the world's population will migrate to Europe. Entire areas of the mideast, Asia, and Africa will become virtually depopulated.
Of course, all those useless, violent, and ignorant immigrants will soon destroy their new countries, but that doesn't seem to bother the European liberals much. Having a multicultural society is so much more important than retaining the fabric of European civilization.