I’ve certainly had some tense conversations with auto companies and their representatives during the last couple of years. But they reacted fairly calmly when I asked them about the monkey research. Volkswagen, Daimler and BMW all distanced themselves from the experiments. After the article was published, all three companies took action against midlevel employees who had been responsible for overseeing the work of the front organization, relieving them of their duties pending internal investigations.

The carmakers’ low-key response to my questions about the monkeys indicates that they may have underestimated what the article’s repercussions would be. I know I did. I thought the story would make a splash, but I didn’t expect it to become the top story in German media for several days; for German Chancellor Angela Merkel to weigh in with an expression of condemnation; and for the German Parliament to hold a debate on the issue.

Why the outrage over the fate of 10 macaque monkeys when Volkswagen had already pleaded guilty to conspiracy to violate the United States Clean Air Act and other charges? After all, we already knew that diesel exhaust has caused hundreds of thousands of people to die prematurely, and that Volkswagen and other European carmakers took advantage of weak enforcement to mislead the public about how much pollution their vehicles produced.

I think the explanation is this: Until the 10 monkeys became part of the story, Volkswagen’s fraud had no identifiable victims. When people die from lung cancer or heart attacks after breathing air polluted by diesel cars, it’s impossible to point the finger at any one carmaker. The ill effects are cumulative and may take years to manifest themselves.

The 10 unfortunate monkeys, forced to breathe exhaust so that Volkswagen and the others could sell more cars, provided the scandal with its first specific casualties. They crystallized public frustration with the auto companies’ behavior.

As the magazine Der Spiegel wrote in an editorial, “The faces of our animal relatives opened our eyes to the unscrupulousness of this industry.”

In Germany, the monkey experiments may prompt action that watchdog groups have been seeking for years. Political leaders, fearful that their longtime acquiescence to the auto industry has become a liability, are talking about forcing all lobbyists to register and disclose their contributions to politicians, as they must already do in the United States. There are increasing calls for car companies to retrofit old diesels with better emissions equipment. And during the debate in Parliament, several representatives spoke of a need for “culture change” in the industry, a hint that they may push automakers to change their management.