Apple Inc. (AAPL) and the ubiquitous coffee king of the world, Starbucks Corporation (SBUX), have caught the eye of European Union regulators, who suspect the companies — along with Amazon.com (AMZN) and Italian automaker Fiat Chrysler (FCAU) — of striking deals with EU member states to illegally reduce their taxable income.

Tax probes by the European Commission, the EU’s governing body, have been very well-covered in regards to AAPL, Fiat and AMZN, but it’s the allegations against the Seattle-based Starbucks that were making waves on Friday.

The EC report, which is dated June 11 but was only just released to the public on Friday, says a tax deal SBUX struck with the Netherlands is under investigation. The EC went on to briefly outline the cases:

• “The individual rulings issued by the Irish tax authorities on the calculation of the taxable profit allocated to the Irish branches of Apple Sales International and of Apple Operations Europe;
• The individual ruling issued by the Dutch tax authorities on the calculation of the taxable basis in the Netherlands for manufacturing activities of Starbucks Manufacturing EMEA BV;
• The individual ruling issued by the Luxembourgish tax authorities on the calculation of the taxable basis in Luxembourg for the financing activities of Fiat Finance and Trade.”

As the investigations regard AAPL, Ireland has ardently defended its deals with the Cupertino, California-based tech behemoth in the past.

The latest string of accusations by the European Commission come as eurozone economies continue to fight an uphill battle to reignite growth in the midst of a continental recession. European stocks were mixed today after third-quarter growth numbers from heavy-hitters in the eurozone failed to impress — but didn’t entirely depress — investors.

France’s GDP grew by a pesky 0.3% in the period, although that pitiful number was still higher than analyst estimates. Italy’s economy contracted in the third quarter, and Germany narrowly dodged recessionary status, growing at a 0.1% pace last quarter.

In short, it’s no coincidence that SBUX, AAPL, AMZN and Fiat are being scrutinized for low-balling tax bills at the precise time that EU member nations aren’t collecting a whole lot of taxes.

To be fair, the liberals across the pond aren’t the only governments cracking down on sweetheart corporate tax deals. Last month I wrote about how two mega-mergers in the healthcare sector — a $176 billion Pfizer (PFE) and AstraZeneca (AZN) union as well as the prospective Shire (SHPG) acquisition at the hands of AbbVie (ABBV) — were essentially dead in the water after the U.S. Treasury put tax-inversion deals under the microscope:

“In an effort to boost tax revenue, the U.S. government is cracking down on “tax-inversion” deals that allow domestic companies to use overseas money to acquire a foreign entity for the sake of tax purposes. Countless companies employ the strategy, which is designed to avoid repatriation fees and the higher U.S. corporate tax rate.”

So what both U.S. and EU regulators seem to be saying to SBUX, AAPL, AMZN and others is this: Just because your friend avoids billions in taxes by wooing foreign governments and exploiting international tax code loopholes doesn’t mean you have to, too.

While there’s nothing wrong with an appeal to morality, it’s going to take more than a lecture on business ethics to get these Wall Street titans to change their tax structure.

If charges are eventually brought against these companies, these stocks could take a nasty turn for the worse.

As of this writing, John Divine owned shares of AAPL stock. You can follow him on Twitter at @divinebizkid.