One of the biggest fashion controversies is whether or not it is acceptable to wear socks with sandals. Most people would claim that the answer is no, and yet there are many people seen wearing this combination on the regular - especially American tourists. Maybe they are confused with the weather or didn't want to pack multiple pairs of shoes, but this is a pretty telltale sign that an American is approaching.
This is a pretty clever solution to having to pack multiple pairs of shoes. Instead of bringing warm shoes and cool shoes, you can just layer on socks.