It is, in point of fact, still illegal. U.S. Code Section 301 describes the proper behavior that should be taken during the anthem.

However, since it’s plainly unconstitutional and utterly unenforceable, there is no punishment for it and it is never prosecuted… because that would end with the courts striking it down.

Call it a symbolic law, if you will.

I happened to write about my own feelings about all of this last weekend.