In violation of Satanic Tenet IV: The freedoms of others should be respected, including the freedom to offend. To willfully and unjustly encroach upon the freedoms of another is to forgo one's own.
Edit: I think I may have written this out to give the incorrect impression. What I mean is that this act of destroying the idol is in violation. Not that the person who did it is being violated upon.
I don't think this would be an actual violation. The freedom originally encroached upon was the TSTs freedom to display their statue. By willfully and unjustly encroaching on that right, the accused forwent their own.