For the most part, you'll find that North Americans refrigerate their butter - just like all of their dairy products.
But, there are a few who refuse to do this. Many people in America store their butter at room temperature on the counter top - much to the disgust of their refrigerating counter parts.
So, who is right?
Well, technically, both camps are right.
According to a related article by POPSUGAR, it's OK to leave butter on the counter, but only a very specific kind.