An antitrust investigation into Facebook led by the New York Attorney General’s office widened Tuesday with the announcement that 47 attorneys general are now taking part in the probe.

The number is a sizeable increase from the nine, including New York, that were on board when the investigation was first announced in early September.

“After continued bipartisan conversations with attorneys general from around the country, today I am announcing that we have vastly expanded the list of states, districts, and territories investigating Facebook for potential antitrust violations,” New York Attorney General Letitia James said in a press release. “Our investigation now has the support of 47 attorneys general from around the nation, who are all concerned that Facebook may have put consumer data at risk, reduced the quality of consumers’ choices, and increased the price of advertising. As we continue our investigation, we will use every investigative tool at our disposal to determine whether Facebook’s actions stifled competition and put users at risk.”

It’s unclear which states are not participating in the probe, as James’ announcement notes there are “a number of other states that cannot confirm their participation in pending investigations.”

Antitrust probes into Big Tech companies are the rage among attorneys general in recent months, with a coalition of 50 taking part in a probe into Google for monopolistic business practices. The launch of the investigations coincides with the Department of Justice itself in July announcing the opening of a review of the power and practices of market-leading online platforms.

Amazon and Apple are other companies believed to be in the crosshairs of regulators.

Facebook is also facing an antitrust investigation from the Federal Trade Commission, the social media giant announced in a second-quarter filing.

“Facebook is a dominant force in the social media industry, and with that dominance comes an obligation to ensure their practices are not stifling competition,” said Pennsylvania Attorney General Josh Shapiro in joining the states’ probe. “Our bipartisan coalition of 46 of my Attorney General colleagues will follow the evidence wherever it leads, and we will not hesitate to take action to protect the rights of consumers.”

“The District of Columbia has joined this investigation to ensure Facebook is giving a fair shake to District residents and the American people,” added District of Columbia Attorney General Karl A. Racine. “No company gets a pass if it throttles competitors and exploits consumers.”

Washington D.C. was one of the original leaders of the investigation, along with Colorado, Florida, Iowa, Nebraska, New York, North Carolina, Ohio, and Tennessee. The new additions to the investigation announced include Arizona, Arkansas, Connecticut, Delaware, Idaho, Illinois, Indiana, Kansas, Kentucky, Louisiana, Maine, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nevada, New Hampshire, New Jersey, New Mexico, North Dakota, Oklahoma, Pennsylvania, Rhode Island, South Carolina, Texas, Vermont, Virginia, Wisconsin, Wyoming, and the territory of Guam.