Let's say that someone had done this to me.  Would me joining in an act that offends many Americans and military families really be changing the culture for the better?  Or would such an act of anti-patriotism actually create a greater divide between those who painted my door and myself?  My point is ... this is not the way to bring about the change they are seeking.  The only way is to dispel ignorance with education and experience.  No one turned from racist beliefs to those of equality because someone burned the flag.  It's a ridiculous "protest" at the wrong symbols and the visual of millionaires carrying it out while on the field is discordant with the message.  If they care enough, they would protest in their unpaid time.  But I don't see them investing even a second of their own time into this cause.  It's hollow.  And they know it.