From the Stupid Things That Annoy Me file:

People who put their babies in carriers/strollers and then cover them up completely. Like they put a blanket over the whole stroller, or somehow close the carrier completely so the baby is in a little closed dark box. I know that when you're outdoors it's to keep out the wind, but you should really let your baby see the world! Actually, it's more for purely selfish reasons - if you're talking up a lot of space with a big stroller or something, I want the compensation of seeing a cute little baby.