In 2016, the European Union decided that Ireland had not charged Apple enough in taxes, and demanded that Ireland collect an additional 13 billion euro (or roughly $14.4 billion) in "back taxes." This would be far from the first time a company, especially a tech company, was accused of avoiding taxes. For example, Bernie Sanders believes that Amazon has skirted tax law in the United States. However, this might be the first time that the country in question believes that the company paid what they were supposed to.
In this case, Ireland is on Apple's side, not the side of the EU. In fact, the Irish government will be heading to court with Apple to argue against the EU's imposed penalties over Apple paying exactly what the country asked them to pay. The EU has essentially argued that Apple has an unfair advantage in Ireland, where the company houses its European headquarters.
Publicly, the issue revolves around how Apple reports profits. Since the company's European headquarters are in Ireland, they report the profit from their various divisions within Europe through their corporate office. This allows them to pay 3.8 percent on their European profits. However, the EU believes that the amount collected should be reflective of the countries in which the company operates, including design and manufacturing.
In 2016, the Obama administration claimed that the EU was trying to help itself to cash that rightly belongs within the United States' economy. Many in Silicon Valley have argued that it is just one example of many of the jealousy of the EU over constantly losing out on the highly profitable tech market, and trying to rig EU regulations against US companies. This argument has been made many times, often referencing the "Google Tax", which has already claimed services in Europe, like Google News.