Spelling errors when typing a URL can be exploited by website-squatters: users are led to phony sites in a phenomenon we call parasitic URL naming. These phony sites imitate popular websites and try to extract personal information from unsuspecting users, or simply advertise and sell products to users. In this paper, we conduct a massive study in order to quantify the extent of this parasitic URL naming We start with a corpus of 900 popular websites, which we refer to as original URLs, and generate roughly 3 million URLs by varying the original names systematically and exhaustively. Over a period of 60 days, we analyze how many sites have URLs very similar to our original URLs. We find that parasitic URL naming is a wide-spread problem and quantify the extent of this issue. We believe that this work will provide the first step towards research and tools to combat web-fraud.