A coalition of US states led by Texas has amended its lawsuit against Google, claiming anti-trust violations through the company’s efforts to boost its dominant advertising business.

The revised complaint includes concerns about recent Google’s privacy updates to its Chrome browser, known as Privacy Sandbox, the tech giant’s use of Chrome, and claims about ways Google hindered ad competition, such as what is said to be an anti-competitive agreement with Facebook.

The states’ attorneys general criticise Privacy Sandbox, which is designed to replace third-party cookies, with Google’s more limited system.

The amended complaint reads: “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 changes are anti-competitive 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.” 

The attorneys general also allege the new scheme will coerce advertisers to shift spending from smaller media companies to dominant players such as Google’s.

“Google is trying to hide its true intentions behind a pretext of privacy [because] Google does not actually put a stop to user profiling or targeted advertising – it puts Google’s Chrome browser at the centre of tracking and targeting,” the lawyers claim.

In January the Competition Markets Authority in the UK began to investigate Google’s plan to remove third-party cookies through Privacy Sandbox on worries it would be anti-competitive. The cookies help businesses target advertising and generate revenue to fund free content.

But as Google could still track consumers’ activity and behaviour through its first-party cookies that raised concerns the company would have an unfair advantage over smaller publishers and advertisers.

The Texan-led lawsuit also alleges the company’s introduction of open bidding for online advertising is a way to foreclose competition by, for example, hindering rivals’ ability to identify users associated with publishers’ ad space in auctions.

Law Street Media reports the attorneys general allege Google and Facebook have a secret advertising agreement to reduce competition, which has caused some publishers to sue the companies.

The states’ initial anti-trust lawsuit in December focused on claims about Google’s anti-competitive practices and “deceptive misrepresentations” regarding its monopolisation of the online ad industry.

The December filing followed the department of justice suing Google in October for purported monopolisation of various markets, including general search services, search advertising and general search text advertising.

GRC World Forums has contacted Google for comment.

PrivSec Global, a live streaming event, takes place on 23-25 March featuring more than 200 speakers and 64 sessions on privacy, data protection and cyber-security.