JoS was the bestselling sex guide that captured the spirit of the 70s sexual revolution. Although it was banned in Ireland, it was openly on sale here. How does censorship work if nobody pays any attention to the law?

JoS was the bestselling sex guide that captured the spirit of the 70s sexual revolution. Although it was banned in Ireland, it was openly on sale here. How does censorship work if nobody pays any attention to the law?
This classic American novel critiques marriage, gender roles and masculinity. So was it the sex or the reproductive choices that attracted the ire of the censor?
Apparently, describing three single girls navigating the NY dating scene was censorship-worthy literature in 1958.
A stalwart of my bookshelves, this book was rediscovered after it featured in ‘Mad Men’.