About 25 defense attorneys have appeared in federal court to represent dozens of hotels, including Marriott and Hilton, in lawsuits alleging they rented rooms to sex traffickers at locations nationwide.

So far, lawyers have filed 25 lawsuits in federal courts on behalf of anonymous victims against various hotel chains, asserting violations of the federal Trafficking Victims Protection Reauthorization Act. The suits, all filed this year, are a growing area for the plaintiffs’ bar.