I've never seen a Muslim in a turban in the US. They're pretty much all Sikhs. Of course, we've had several morons shoot or shoot at Sikhs because they're too stupid to know they're not Muslims.
Yes, you're absolutely right; I, too, have not seen Muslims sporting full turbans over here. The posting was meant to convey a figurative allusion (conjuring up images of Taliban thugs, etc.). And although I do not have any direct experience with Sikhs or Sikkhim, my former supervisor, who was Indian, spoke very highly of them, and even indicated that they are generally very conservative and usually support Republicans in elections. Those folks must NEVER be targeted along with Muslims because of ignorance or confusion!