The value of trademarks

After pioneering the concept and terminology of Suburban Tramping, I was shocked to see some joker (a musician) inviting people to his gig and myspace page (http://www.myspace.com/urbantramper) with the name Urban Tramper. Of course, this is slightly different from my term, but the juxtaposition of ideas is identical.

What's next? "The Mountain Crawlers"?