As regards the two flags.
1st, it is probably a simple matter of the employees at the Walmart in question not recognizing the ISIS flag. As simple as that. The Confederate Flag is well known throughout America and Walmart recently enacted a direct policy against it.
2nd, I think it is the height of folly for people, because of political correctness, to try and erase history. The Confederate Flag is a part of American history. It is true that it was a symbol of the Confederacy, but for more years than it was that, it has been a state flag, a southern culture emblem. Each state has a legislature that is elected by the people. If the people do not want it as their state flag...that is fine. Their legislatures will take care of it which I have no problem with.
But there are movement's afoot to take it out of history books. To have town ordinances banning its very appearance. To take it off old southern monuments. etc. I have a real problem with such attempts to erase history.
We give people the right in this country to burnt the American flag. I do not like it when I see it...but we allow it nonetheless. If some old boy from Alabama wants to hang the old Confederate flag in his car window...I say big whoop. Let him do so.
But that's just me.