This is something that I've been thinking about on and off for months. It always surprises me.
Now, when I say that someone has a nickname as their surname, I'm talking about them having a surname that is typically a nickname for a first name. For example, a friend I had in elementary school had the surname "Luke", as in the nickname for Lucas.
Other examples of nicknames acting as surnames that I have seen are Jenny, Kenny, Matt, Ray, Steve, and Terry.
Does anyone else get surprised by these names? More importantly, does anyone have any more?