Indonesia is the 4th largest country in the world (by population) and it is predominantly Muslim.  The girls start wearing their head coverings very early - elementary school or so - and it's not uncommon to see groups of them walking to and from school.  They must study at least a little bit of English because each time I passed a group of them, I would hear "nice to meet you mister" or "have a nice day mister".  They were all very nice and I didn't feel the least bit uncomfortable.  When they saw my camera, the asked for a photo - you guessed it - for their facebook.  These two refused to smile but as you can see, I almost got the one on the left!