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Good morning.

Here’s what you need to know:

“This merger would greatly harm American consumers.”

• That’s the top antitrust regulator at the Justice Department, which sued on Monday to block AT&T’s $85.4 billion bid for Time Warner.

AT&T, which has a long history of run-ins with the government, defended the deal, arguing that the companies aren’t direct competitors and that the government hasn’t challenged a similar kind of merger in decades.

• If allowed, the deal would create a media and telecommunications behemoth. AT&T is one of the largest internet and telephone providers in the U.S., and Time Warner’s properties include HBO, Warner Bros. and Turner Broadcasting, which includes CNN.