A bipartisan group of lawmakers have asked that the FTC continue its antitrust lawsuit against Facebook after setbacks in court. Senators Amy Klobuchar (D-MN) and Mike Lee (R-UT), together with House representatives David Cicilline (D-RI) and Ken Buck (R-CO), signed a letter addressed to FTC Chair Lina Khan detailing why the regulatory action is needed.

“It is essential that the Commission take action to deter anticompetitive conduct by digital monopolists by ensuring that they are held liable for antitrust violations to the full extent of the law,” the lawmakers wrote.

This letter comes just four days after Judge James E. Boasberg dismissed the federal government’s key antitrust complaint against Facebook on Monday, as well as a complaint from 48 state attorneys general.

The FTC has until July 29th to refile its complaint, although it will have to offer more comprehensive evidence that Facebook does indeed wield monopoly power in social networking. In the Monday dismissal, Boasberg wrote he was unimpressed with the FTC’s attempt to classify Facebook as a monopoly, as the initial complaint only provided “the naked allegation” that the social media giant had a 60 percent market share.

The dismissal does offer some metrics that might be persuasive to the court, like how much users spend on Facebook apps, or an explanation of Facebook’s competition in the sector. However, each of those suggestions are caveated with how examples of how difficult these metrics can be to prove.

In the dismissal, Boasberg also noted how difficult it was to fit Facebook’s service into the existing antitrust regulations.

“This case involves no ordinary or intuitive market,” he wrote. “Rather, PSN [Personal Social Networking] services are free to use, and the exact metes and bounds of what even constitutes a PSN service — i.e., which features of a company’s mobile app or website are included in that definition and which are excluded — are hardly crystal clear.”

This point hasn’t been lost on lawmakers, who have rallied around changing antitrust law to better address modern tech giants. Buck, one of the letter’s signatories, tweeted Monday that the dismissal showed antitrust reform is urgently needed.

“Congress needs to provide additional tools and resources to our antitrust enforcers to go after Big Tech companies engaging in anticompetitive conduct,” he wrote.