On Monday, the US Department of Justice (DOJ) announced nine states, including Michigan and Nebraska, have joined a DOJ lawsuit against the search giant Google and parent company Alphabet. The lawsuit alleges that the search engine company violated antitrust laws in how it ran its digital advertising business.

Arizona, Illinois, Michigan, Minnesota, Nebraska, New Hampshire, North Carolina, Washington and West Virginia all joined the DOJ lawsuit, according to the announcement.

Filed in January by the Department of Justice, along with eight states, the lawsuit asserted that Google should be forced to sell off its ad manager suite, since it illegally abused its control over the online advertising environment. Google has denied all the charges, and requested Judge Leonie Brinkema of the Eastern District of Virginia dismiss the case.

This is the second such lawsuit the search giant has faced. A separate lawsuit filed at the end of the Trump administration in 2020, accusing Google of violating antitrust laws to maintain its dominance of the search engine sector, is set to go to trial in September.

The Biden administration has been toughening the enforcement of antitrust laws, with multiple other such challenges of proposed mergers pending.