Is street harassment a problem in the U.S.?

Yes, it's a significant problem. Personally I hate that often I can't just normally walk in NYC without being disturbed. There is a big difference between a compliment and harassment. You can say simple "How are you this morning?" the way it's nice and the way it's offensive. Unfortunately some men pretend they don't understand this. Not only this, but they try to turn it around and say that women who don't like such compliments are strange. It's very unfair, and yes, they know it as well.