By the way, here's what I say in my syllabus about the alienation of affections and criminal conversation. I hope the "pedagogical goals" section helps explain why I've decided to include it, though part of the reason is just that it's a fun subject that's likely to get students excited, which is especially important late in the semester.
Alienation of affections basically consists of a defendant's (1) wrongfully (2) causing plaintiff (3) to lose the affection and often company of the plaintiff's spouse. In principle, it could apply to supposedly meddling in-laws, and has sometimes been applied that way, though if the in-laws are looking out for their married child's best interest such behavior might not be "wrongful." In practice, it has generally been applied to lovers who seduce one spouse away from the other (if it can be shown that they caused the alienation, rather than that a preexisting alienation of the spouses caused one spouse to be interested in the defendant's attentions). The related tort of criminal conversation basically consists of a defendant's having adulterous sex with plaintiff's spouse; but for our purposes, we'll treat that as a subset of alienation of affections (which is indeed the approach in some states).
These torts have been largely abolished, but remain recognized in Hawaii, Illinois, Mississippi, New Mexico, North Carolina, South Dakota, and Utah. And they are not infrequently litigated, especially in North Carolina: A 2006 article in the Greensboro News & Record reports that "People filed an average of 245 such suits per year in North Carolina between 2000 and 2005, according to data provided by the state Administrative Office of the Courts."
By way of comparison, the well-established right of publicity tort seems to be litigated much less often (2 cases since 2000 in the NC-CS and NC-TRIALORDERS Westlaw databases, as opposed to 38 for the alienation of affections). Even on a national basis, an ALLCASES search for sy("right of publicity" ((misappropriat! appropriat!) +5 (name likeness image))) & date(> 1/1/2000) yielded 150 cases, while sy((alienat! +3 affection) "criminal conversation") & date(> 1/1/2000) yielded 66, of which 50 were in jurisdictions that still recognize one or both of those torts. So there's life in this old tort yet, though query whether there should be.
Pedagogical goals: (1) Throughout most of the class, we've discussed how tort law has substantively expanded, so that formerly nontortious behavior is now treated as tortious. It's easy to assume, even unconsciously, that this trend is natural, irreversible, and right. But these torts help illustrate that torts could also be abrogated, either through judicial or statutory decision. (This has also happened in narrower contexts as to negligence and strict liability—consider, for instance, some tort reform proposals that have capped damages.) And considering the rejection of these torts might lead us to ask, especially in the coming units: Should any other torts be rejected or dramatically narrowed as well?
(2) The rejection of these torts also leads us to ask: Why would courts or legislatures reject liability for behavior that is pretty clearly wrongful (which adultery is, even if some forms of alienation of affections might not be), and that is pretty clearly emotionally damaging to the victim? Did they conclude that the damage wasn't real enough, because it isn't physical? (That would also bear on some of the other torts we've been discussing in the last few units, and that we'll discuss in the coming units.)
Did they conclude that the behavior should be within people's zone of liberty? (Why would that be so, about adultery? Also, should the same rationale apply to some of the other torts we discuss below?) Did they conclude there were especially severe problems of proof for these torts but not others? Did they have any other reasons?
(3) And we should be open to the possibility that the progress of the law here has been mistaken, and should be reversed. Should states readopt the torts. Why, or why not?