More than one year after the European Union hit Google with a record $2.72 billion antitrust fine over search engine abuses, regulators are reportedly on the verge of levelling an even larger fine related to the Android mobile operating system.

While the fine could technically be as high as $11 billion, it likely won’t be that large. But many observers are betting it will be bigger than last year’s.

So what’s this case all about? How can a company be accused of abusing a product that’s free?

Here are five things to know about the case ahead of the decision, which is expected to possibly land later this week:

  1. The charges: Almost two years ago, EU regulators accused Google of using Android to try to extend its dominance in desktop search to mobile. Because smartphone manufacturers are often required to install Google products, such as its Chrome browser and search app and apps like YouTube, the EU is arguing that the company is limiting competition.
  2. But, but, but …: Naturally, Google begs to differ. The company argues that the launch of Android in 2007 not only helped numerous handset makers jump into the smartphone revolution, it enabled the creation of those devices at dramatically lower costs and ensured that there would be robust competition against Apple’s iPhone and iOS ecosystem. Plus, there’s nothing stopping users from downloading other apps. As Google likes to say, competition is just a click away.
  3. Maybe, but still …: While the EU may concede some of those points, it counters that in many cases Google’s contracts with handset makers are too binding, and sometimes include…