Google was recently slammed by 36 antitrust lawsuits in the US over its dominating the Play Store on Android platforms. Now, CNET reports that it’s been served another antitrust lawsuit by two Massachusetts companies accusing it of giving Facebook an unfair advantage in online advertising.

Google gets served

The suit is calling for “class-action status” for other advertisers that the plaintiffs believe were damaged by Facebook and Google’s collusion, which has been alleged since December of last year.

According to CNET, Facebook threatened that it would pursue a technique of ad buying called “header bidding”, also known as advance bidding, which is also the major alternative to Google’s method of “waterfall” ad buying. Waterfall buying ensures that the first-in-line advertiser is sold ad space, whereas header bidding gives it to the highest bidder. And Facebook has a lot of dough to bid.

According to the lawsuit, the search engine and internet giant offered Facebook “special information, a speed advantage to assist Facebook in succeeding in the auctions, and a guaranteed win rate,” in supposedly fair ad auctions.

Furthermore, Google allegedly agreed to fix prices and specifically allocate markets to Facebook in auctions for in-app and website advertising space, and “given the scope and extensive nature of cooperation” between the two platforms they were aware they could be in violation of antitrust laws.

Both parties have brushed off previous similar allegations, with Facebook at one time telling CNET that partnerships between big names in this industry are commonplace. Facebook, ever the centre of bad publicity, has also been caught banning several NYU researchers from investigating its targeted political ads.