Regulators at the United States Department of Justice don’t sound very keen on the idea that America’s hottest wireless carrier should get bought up by the wireless world’s perpetual loser. Unnamed sources tell The Wall Street Journal that DOJ regulators indicated to SoftBank CEO Masayoshi Son and Sprint CEO Dan Hesse that they were cool to the idea of a Sprint-T-Mobile merger during a recent meeting with the two executives. The Journal’s sources say that “U.S. antitrust authorities regard the current lineup of four national mobile-phone carriers as important to maintaining a competitive market, and department officials indicated at the meeting that a deal combining Sprint and T-Mobile could face regulatory difficulties.” Even so, the Journal says that this meeting hasn’t dissuaded