The Banner was wrong and should not have been displayed because the message is racist.
In fact I will go so far as to say it is equally as racist as the phrase:-
Black Lives Matter
No-one should be using either phrase to be fair to everyone the phrase:-
All Lives Matter
should be used instead.
But none of Margaret's 'woke' people will agree with me and will continue to insult many people that stand for the national anthem rather than grovel on one knee.