Google was hit with a new antitrust complaint Wednesday, fresh from EU regulators who say the search giant may need to sell part of its online advertising empire. The formal statement of objections ratchets up pressure as Google contends with two other antitrust cases in the US over the same issue, one from the federal government and another from a coalition of state attorneys general.

“We are concerned that Google may have illegally distorted competition in the online advertising technology industry, also known as ‘Adtech,’” said Margrethe Vestager, Executive Vice President of the European Commission, speaking at a press conference. “A remedy requiring Google just to change its behavior would allow Google to continue doing what it has been doing so far, just under a different disguise. Should the Commission conclude that Google acted in an illegal manner, it might require Google to divest part of its services.”

European law sets the maximum penalty for antitrust violations at 10% of a company’s global sales, though fines rarely get that high. Google has paid a total of about $8.6 billion over three previous EU complaints over monopolistic practices in the past, however, so it doesn’t have a great track record. If Europe gave out loyalty punch cards for legal complaints, Google would be well on its way to earning a free antitrust case.

“There is nothing wrong with being dominant as such. What our investigation has shown though, is that Google appears to have abused its market position,” Vestager said.

Google — which by its own estimate takes 35% of every dollar spent on digital ads — did not immediately respond to a request for comment. The company has long argued that such antitrust concerns are unfounded.

After the US Department of Justice filed its antitrust case in January, Google published a blog post describing such lawsuits as an “attempt to pick winners and losers in the highly competitive advertising technology sector.”

Online advertising is complicated, but the simple version of the antitrust argument is Google dominates every corner of the business, paving the way for an unfair advantage over competitors.

Here’s a little background. When you see an ad on the internet, you’re usually looking at the results of a nebulous chain of interconnected systems. In ad tech, there are “buy-side” platforms—marketplaces where advertisers go to buy space to show their ads. There are also “sell-side” platforms, where publishers go to sell the ad space they have on websites and apps. In the middle are systems called “exchanges,” which are platforms that connect all of the buy-side and sell-side platforms together.

Google operates the leading buy-side platforms. It also operates the leading sell-side platforms. Guess who operates the most popular ad tech exchange? A company based in Mountain View, CA called Google. The tech giant knows exactly how much advertisers are willing to pay and exactly how low publishers are willing to set their prices. Google uses that information to preference its own services and route the maximum amount of ad dollars through its pipes, allegedly.

The EU complaint argues that Google set up its buy-side and sell-side platforms to illegally favor its own ad exchange, which is called AdX. For example, the EU complaint says Google let its system place bids for AdX after everyone else’s bid was already in, so AdX could beat its rivals in favorable auctions. Practices like these ensured ad tech customers would have to use AdX, allowing AdX to charge higher fees than it would be able to otherwise, the complaint said.

As if that wasn’t enough, Google also sells its own ad space on services such as Google Search and YouTube. That means Google competes with other companies in bids for the most profitable ads, bids that take on platforms that Google controls.

“Google is representing the interests of both buyers and sellers. At the same time, Google is setting the rules on how demand and supply should meet,” Vestager said. “This gives rise to inherent and pervasive conflicts of interest.”

The company knows this kind of looks like a problem. The US Department of Justice uncovered one damning example in 2016 email sent by a Google executive, asking, “is there a deeper issue with us owning the platform, the exchange, and a huge network? The analogy would be if Goldman or Citibank owned the [New York Stock Exchange].”

As a consumer, you might wonder why you should care. So what if a bunch of ad tech business boys can’t make a few extra dollars? But the ad tech economy is the backbone of the internet, and if Google slurps up all the profits, that makes it much harder to run a company that makes all the content you enjoy (such as Gizmodo, your favorite website, for instance).

“There’s very little consumption that happens on the internet and mobile devices that Google doesn’t have a view of,” said Jason Kint, CEO of Digital Content Next, a trade association that represents roughly 80 publishers, including the New York Times, Wall Street Journal, and Gizmodo’s parent company G/O Media. “Theres an overlap with the way they collect and use data that’s more extensive than any other company on the planet, and regulators are finally recognizing the problem.”

In 2022, Google’s ad business made over $224 billion dollars, the vast majority of the company’s revenue. Multi-billion dollar fines sting no matter how big your market cap, though Google can weather the hit. The bigger concern is a looming threat that one of these pesky regulators might force Google to break up its tidy businesses. In the past, that seemed like a fantasy reserved for the most optimistic big tech critics, but as the lawsuits stack up, it’s beginning to look like a real prospect.

“A breakup is certainly possible, especially with the case in the US,” Kint said. “How that happens is a different question.”

The worst case for Google would be the US or the EU forcing the company to divest some or all of its advertising businesses. Alternatively, Google has hinted at the possibility that it might try to stave of regulators through a sort of internal breakup. In theory, Google could split off its ad business away but keep it under the ownership of Alphabet, Google’s parent company. Under that scheme, the company could set up a sort of firewall of information meant to prevent self-dealing.

However, Vestager suggested that more friendly approach isn’t likely to solve the problem. The online ad business is so technical that it’s easy to hide wrongdoing, so a solution that only requires behavior changes won’t be enough. “We have seen this play out concretely: each time a practice was detected by the industry, Google subtly modified its behavior so as to make it more difficult to detect,” Vestager said. “Should the Commission conclude that Google acted in an illegal manner, it might require Google to divest part of its services.”

Antitrust concerns have already sparked major shifts at Google. The company is in the middle of a years-long effort to kill-third party cookies, the primary way websites have tracked users since the dawn of the internet. Google plans to replace cookies with a variety of tools developed in a project called Privacy Sandbox. Along the way, the company is bending over backwards to prove that its Privacy Sandbox features won’t give Google yet another advantage. As part of that effort, the company agreed to make monthly reports to yet another antitrust watchdog, the UK’s Competitive Markets Authority.

No matter how the mounting monopoly cases play out, it’s a disastrous situation for Google. An antitrust case is a major handicap, and now Google has three of them. The increased scrutiny over your efforts to crush the competition makes it a lot harder to, you know, compete. It’s sometimes called the “policeman at the elbow effect.” You have to move slowly and deliberately to when regulators are watching. It couldn’t come at a worse time, as AI technology built by companies like OpenAI poses the only real threat Google has seen since the salad days of Yahoo and Ask Jeeves.