What I particularly don't like about this flag is the raising black (darkness). Do you remember this classic Deutsche Bank logo. It states increasing results. It's that simple. I occassionaly flip the flag over for that reason. More yellow, meaning more light to the equation.
It's for the same reason that I love to flip over the A. It becomes like the V but without the dash.
What I ponder about is your statement "And if millions of people were being oppressed [..] in the name of Santa Claus, maybe an anti-Santa flag would be understandable." And this Santa to me being educational theorists and terrorists like incumbent politicians and bureaucrats are. So we talk mostly about statists. I just don't have an idea for a good graphic art to showcase it to the ones who are not blinded enough to already see.
Oh, maybe it's a good idea to flip the flag back over and think of turning black more and more of this dazzling light that all these statists toot like crazy.