I m not quite sure that how Magento is taken off sites like MagentoThemes.com. How if I using a domain like MAGENTOmilks.com and my product is fresh milk selling?
While there’s no conflicts (not in the same product and services classes as Magneto), the domain name magentomilks.com should be legal and allowed. For the case of MagentoThemes.com, the only issue could be that they are offering commercial magento themes.
Anyway, Domain name conflicts are existing in the cyber world for years, and there’s gray area in the cyber law system as it is much more complicated that normal law. If the offenders have enough financial backup (to pay for solicitors), many cases could be a long long battle.
A Link for your reference, and there’s plenty of such similar cases publish on the net.