The attorney general for Washington, D.C., sued StubHub on Wednesday, accusing the ticket resale platform of advertising deceptively low prices and then ramping up prices with extra fees.

The practice known as “drip pricing” violates consumer protection laws in the nation’s capital, Attorney General Brian Schwalb said.

“StubHub intentionally hides the true price to boost profits at its customers’ expense,” he said in a statement.

The mandatory “fulfillment and service” fees are hidden until the end of a lengthy online purchasing process that often requires more than a dozen pages to complete as a countdown timer creates a sense of urgency, Schwalb said.