Not every trademark application filed with the US Patent and Trademark Office is approved for registration. In the case of "Amish Mafia" for a television series, the trademark examining attorney determined the mark was disparaging to members of the Amish religious sect and issued an office action and final refusal barring registration by owner Discovery Communications, LLC. Discovery appealed the decision to the Trademark Trial and Appeals Board.
Interestingly enough, clothing featuring the "Amish Mafia" brand must not be disparaging. A registration issued for "Amish Mafia" for t-shirts in 2012. Discovery acquired this trademark registration from Daniel A. Wiesner. Discovery offers a full line of "Amish Mafia" t-shirts and other merchandise at the Discovery website.
You can learn more about potentially disparaging trademarks from the Trademark Trial and Appeals Board's recent ruling regarding the Washington Redskins trademarks.
Also, Texas trademark lawyer Tamera Bennett and Los Angeles TV lawyer Gordon Firemark discuss both cases in the 53rd episode of the Entertainment Law Update Podcast.