what does this sentence mean?

the author is Martin Lamber S.

"Silent Spring" was a book published in 1965 by Rachel Carson, a biologist, which is often credited with getting environmental awareness and the ecological movement started. Among other things, she found that the insecticide DDT had the unintended consequence of causing shell thinning in birds' eggshells, which made them much more fragile and caused bird populations to plummet. The book caused people to look much more intensely at what we were doing to the plantet. It's been heavily controversial ever since, because the right wing in America still thinks it's a plot to destroy the capitalist system and that there never has been any environmental problem. Apparently your quote says there was a court case at about the same time which was equally important. Parenthetically, what case are they talking about?