I asked my dog about this, and she had some good points:
First of all, that's Duplo not Lego.
Second of all, "the means to my Lego"?
Third of all, theft is theft under both capitalism and socialism. If he didn't have an agreement with his dad that his dad could take half the tower, the dad is simply a thief. And theft is theft under both systems. And if his dad is supposed to represent "the government" or something, and taking half his stuff is supposed to be taxation, taxation happens under both capitalism and socialism.