StubHub is accused of duping customers over ticket prices in a new lawsuit filed by the Washington, D.C., attorney general. The lawsuit, filed in Superior Court of the District of Columbia, alleges that the secondary ticket platform conceals true costs using “drip pricing”: a series of unnecessary steps in the checkout process, where fees accumulate without explanation until the transaction has been completed—all while a timer creates a sense of urgency. Fees designated as “fulfilment and service,” the suit adds, are in fact flexible mark-ups, sometimes tied to supply and demand.

Brian Schwalb, the attorney general, wants a court order to force Stubhub to simplify its checkout process and to disgorge more than $100 million in profits from hidden fees, plus damages. He says the practice violates D.C. consumer protection laws, deceiving customers and making it impossible to compare costs between platforms.

The lawsuit notes that, in 2014 and 2015, StubHub tested a more transparent “all-in” pricing model but found it could maximize profits by keeping fees hidden. While StubHub does offer a preview of ticket prices with all the mandatory fees, it is hidden behind multiple drop-down menus that users are unlikely to explore, according to the lawsuit.

The move follows extensive investigation into the business practices of Ticketmaster parent Live Nation, culminating, this May, in a lawsuit brought by the United States advocating for the breaking up of Live Nation Entertainment.