Complex sentence: In 2008, Nielsen Holdings challenged Truck Ads right to publish its media market maps by alleging that Truck Ads was unlawfully using A.C. Nielsen's designated market area (DMA) maps on truckads.com.
Split into simpler sentences: In 2008, Nielsen Holdings challenged Truck Ads right to publish its media market maps. They alleged that Truck Ads was unlawfully using A.C. Nielsen's designated market area (DMA) maps on truckads.com.