Using loadUI for loading other people's sites

Usually tools for load testing ask to create a folder on the server or something like that in order you can only load your sites, not attack other people's sites. I downloaded your tool yesterday, and I like it - it's really easy-to-use, but this question's keeping me on the alert. Please, answer it!
P.S. Sorry, if I'm not the first one with such a question and there's already an answer for it! Thanks in advance.