Dr. Woods may have a better answer, but I just finished reading For a New Liberty, and I have a couple ideas on what he may have meant. I believe abortion is by far the most controversial since readers may actually disagree with Rothbard’s position. However, he also discusses pornography, sex, gambling, and drug laws. Of course, in these passages he is not claiming any particular actions are moral, he is only claiming that people should not be locked in cages for engaging in voluntary actions. These topics are discussed in Chapter 6, entitled Personal Liberty. That chapter also contains much less controversial topics including speech, media, wiretapping, and police laws. I very much enjoyed the book, but I was already a libertarian. I can definitely see the section on abortion being a problem even for some libertarians. The other topics may be uncomfortable to discuss with your grandmother, but I do not think many libertarians would disagree with Rothbard’s position.