If a usage predates microsofts, then they probably wouldn't have a good claim, however, once a trademark receives "uncontestable" status, there are limitations on expansion of a prior usage (i.e if you owned a little cafe called "Starbucks" and you were using it first, didn't contest the trademark filing, you couldn't decide to open up a chain of coffee stores - but could continue to operate your original store). There is also nothing stopping a company for filing a lawsuit against someone resulting in large legal fees - fees that would not be able to be recovered in most cases. Mike Rowe (real name) found this out when he registered MikeRoweSoft.com (phonetic, misspellings, and even foreign spellings can be ruled trademark infringement. You also do not have the right to use your real name if it infringes upon an existing trademark i.e. even if your real last name was "Trump" you couldn't open a casino called "Trump Casino". If someone is thinking about registering a domain in hopes of getting traffic because of a popular trademark, then it's probably infringement. The TLD makes no difference. Adding words to a trademark i.e. MySpaceCodesandCheats is still infringement because it contains the trademarked term. Federal Trademark holders can get treble legal fees, damages, and any income that was generated from the infringing site. Trademarks are granted by classification - there are actually several owners of trademarks on "MySpace" or "Apple" but each has a different usage (classification). There are some companies (IBM) which have broad protection (trademarks in every class) which effectively prevent any usage of their trademark.
Microsoft is going after domains such as microsoftofficehome.info freemsnhotmail.com funnymsn.com gamesonxbox.com and other sites that use PPC ads for the sole purpose of making money. Microsoft has called them by the lowest internet classification possible: cybersquatters. http://www.microsoft.com/presspass/features/2006/aug06/08-22domaindefense.mspx Skinny
When people get domains that have trademarked names as whole or part of the domain name. I am all for companies going for all domains that include their names and trademarks. Why should these types of websites make money off the parent company?
Blizzard Entertainment was doing the same at some time..and they were sending some funny smail to domain owners.