The DOJ has voiced several antitrust concerns this year, including an action to prevent H&R Block, Inc. ( HRB ), the largest U.S. preparer of taxes, from acquiring 2SS Holdings Inc, the developer and owner of TaxACT. The DOJ also voiced concern over the merger between Nasdaq OMX Group ( NDAQ ) and NYSE Euronext (NYX). These concerns aim to foster competition as to innovation, but primarily involve an interest in keeping prices down. AT&T has claimed that the proposed M&A activity would provide better service to a larger area, by combining the networks and consolidating future development costs. The DOJ argues that T-Mobile USA is an important market competitor, whose absence would lessen pressure to keep profit margins low and/or improve service. "This lawsuit seeks to ensure that everyone can continue to receive the benefits of that competition," according to Deputy Attorney General James Cole.