Shortly after the Department of Justice announced in early July that it had opened an investigation into alleged collusion between major airlines to keep ticket prices high two groups of passengers filed lawsuits against the major U.S. carriers. Since then, the legal system has been inundated with strikingly similar complaints from travelers.

According to the Dallas Morning News, 75 different lawsuits have been filed against Delta, America, United, and Southwest since July 1, when the DOJ revealed its antitrust probe.

The legal actions, which have been filed across all corners of the U.S., use the DOJ’s investigation as a basis for allegations that the airlines colluded to keep fares high through a series of mega-mergers.

The four airlines named in the lawsuits have undergone major mergers in the last decade and now reportedly account for 80% of all domestic air travel.

Back in 2008 Delta merged with Northwest Airlines; in 2010 Southwest acquired AirTran; United merged with Continental Airlines in 2012; and American and U.S. Airways finalized their merger in 2013 but have not yet combined all operations.

“This action challenges a collusion among major airlines to limit routes, information and available seats to keep airfares artificially high,” the first lawsuit to be filed in New York states. “Plaintiffs allege that defendants illegally signaled to each other how quickly they would add new flights, routes, and extra seats. To keep prices high on fares, it was undesirable for the defendants to increase capacity.”

While it’s possible that the lawsuits could be consolidated into one mega-class-action suit, for now they move forward individually.

So which area of the U.S. has seen the most complaints files? That would be a tie between the Eastern District of New York, Brooklyn and the Northern District of California, San Francisco, which each have 15 cases pending.

Of course, the home bases for many of the major airlines have seen several legal actions files. The Northern District of Texas – home to Southwest and American airlines – has four lawsuits, while Chicago – the home of United Airlines – counts nine suit on its docket. Delta’s home area of Atlanta has only one lawsuit filed, the Dallas Morning News reports.

The District of Minnesota has compiled 11 class-action suits, counting a wide-range of plaintiffs from Minnesota, New Jersey, Minnesota, Missouri, Michigan and San Diego County.

You can check out a full list of the filed lawsuits via the Dallas Morning News.

Guess how many antitrust lawsuits have been filed against the Big 4 airlines (No, more than that – guess again) [Dallas Morning News]

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