Rough waters ahead: Imagine the logistical nightmare that would ensue if AT&T's mega merger with Time Warner were to be undone. The potential ramifications here are huge and involve several entities, not to mention the precedent it could set. Rest assured, this battle is far from over.

The U.S. Department of Justice on Thursday filed an appeal to challenge a federal judge's ruling last month that paved the way for AT&T's mega merger with Time Warner.

On June 12, U.S. District Court Judge Richard Leon cleared AT&T's $85 billion acquisition of Time Warner, imposing no conditions on the deal. The DOJ in November had filed litigation to block the merger but was struck down by the judge's ruling.

AT&T wasted little time, finalizing the merger just a couple of days later. Apparently, the DOJ isn't ready to give up the fight just yet.

AT&T issued the following statement on the matter in light of today's appeal.

"The Court's decision could hardly have been more thorough, fact-based, and well-reasoned," said AT&T General Counsel David McAtee. "While the losing party in litigation always has the right to appeal if it wishes, we are surprised that the DOJ has chosen to do so under these circumstances. We are ready to defend the Court's decision at the D.C. Circuit Court of Appeals."

AT&T announced a new streaming video product, WatchTV, one week after finalizing the merger. Shortly after, AT&T quietly raised administrative fees on consumers' wireless bills and hiked the price of its DirecTV Now service by $5 per month although in fairness, the latter was likely done in "response" to Sling TV's price bump a few days earlier. Sony answered with a price hike of its own for its PlayStation Vue service.