Attorneys general from four states and Puerto Rico joined the Texas-led lawsuit against Google, including Nevada Attorney General Aaron Ford, the first Democrat to join the effort.
Alaska, Florida, Montana and Nevada, which all have Republican attorneys general, also joined the lawsuit on Monday, bringing the total number of plaintiffs to 15 states and territories.
“Our coalition looks forward to holding Google accountable for its illegal conduct and reforming Google’s practices in the future. And we are confident Google will be forced to pay for its misconduct through significant financial penalties,” Texas Attorney General Ken Paxton said in a statement Tuesday.
The lawsuit filed in December alleges Google has violated federal and state antitrust and consumer protection laws. The Texas-led suit focuses on allegations that Google stifled competition in the advertising technology market.
In the updated complaint filed Monday, the states also target Google’s plans to phase out its tracking features that use third-party cookies.
Google said earlier this month it will not build alternative methods to track users after phasing out third-party cookies. The move would limit companies from using third-party cookies on Google's dominant Chrome browser.
“Google’s new scheme is, in essence, to wall off the entire portion of the internet that consumers access through Google’s Chrome browser,” the states said in the complaint.
“Overall, the changes are anticompetitive because they raise barriers to entry and exclude competition in the exchange and ad buying tool markets, which will further expand the already dominant market power of Google’s advertising businesses,” they added.
The Texas-led suit targeting Google’s power in the advertising technology market is just one antitrust legal battle the Silicon Valley giant is facing.
A day after the complaint was filed last year, a bipartisan group of 35 states and Washington, D.C., Guam and Puerto Rico filed an antitrust lawsuit against Google over Google’s search market power.
The state-led efforts followed a lawsuit the Justice Department filed against Google over its search policies.
Google has pushed back on the allegations.
In response to the Texas-led complaint, a spokesperson for Google at the time said “Attorney General [Ken] Paxton’s ad tech claims are meritless.”
“We will strongly defend ourselves from his baseless claims in court,” the spokesperson said.
Between the two state-led lawsuits and the Justice Department effort, every state except Alabama has joined a legal effort targeting Google.
Congress is also weighing options to address what some lawmakers see as an abuse of online market power. The House Judiciary antitrust subcommittee, which released a report last year accusing Google, Apple, Facebook and Amazon of stifling competition, is holding a series of hearings on the issue.
The next House antitrust hearing will be held on Thursday.
Updated 12:56 p.m.