You can probably get away with using it in the URL too, but that becomes a gray area and really will depend on context. As soon as you want to put anything on merchandise though, it becomes really tricky.
An example, if you're a massive fan of a specific brand and start a forum at [brand]-fanclub.com as a hobby, for other fans to share info, you'll probably be ok, since that would be fair use. If you use the same name to start a paid website where people can buy a membership to get the latest news and you start selling branded t-shirts, you might get sued at some point.
You can probably get away with using it in the URL too, but that becomes a gray area and really will depend on context. As soon as you want to put anything on merchandise though, it becomes really tricky.
An example, if you're a massive fan of a specific brand and start a forum at [brand]-fanclub.com as a hobby, for other fans to share info, you'll probably be ok, since that would be fair use. If you use the same name to start a paid website where people can buy a membership to get the latest news and you start selling branded t-shirts, you might get sued at some point.