From an interview with Barbara Wallraff, who is, among other things, a member of AHD's usage panel and the author of Word Court: Wherein Verbal Virtue is Rewarded, Crimes Against the Language are Punished, and Poetic Justice is Done and of her recently-published second book, Your Own Words.

Interviewer: I am also struck that there is a constant purr of interest in word and grammatical issues. For instance, Lynne Truss's book [Eats, Shoots and Leaves] is a surprise bestseller coming out of Britain.
Ms. Wallraff: You will please note that even the subtitle of that book is mispunctuated according to the rule that it gives in the book "A Zero Tolerance Approach to Punctuation." Everybody will tell you that a 'zero-tolerance approach' ought to have a hyphen in it, between zero and -— even Lynn Truss, when she talks about that kind of thing in the hyphen section. So, that's a real "Do as I say not as I do" kind of book.