Yes, the USSC ruled it was OK to pull down a US flag (owned by the US) and burn it as some form of political protest.
No doubt the USSC might draw the line at burning a justice' robes (particularly if the justice were still in them), and might even object if someone burned down the Capitol Building, but in their decision, they did not affirm that the law prohibited vandalism as well.
Congress-critters and the President should continue to beware of the USSC until it comes up with some reason why individual political protest at the expense of the general public is not Constitutional.