Norm Cascades and the Principle of Lenity

If you’ve been following the news over the past few weeks, you’ve seen the story of Cecil the lion, a particularly beloved conservation animal that was lured out of his preserve by an American dentist and brutally killed.  The public outcry and backlash has been enormous.  The dentist’s family has been threatened, he’s gone into hiding, and his business has been shuttered–for now temporarily; perhaps permanently.

Several commentators have noted that despite the relatively horrific circumstances of Cecil’s death, it’s troubling the degree to which a mob mentality has already convicted his killer and punished him with incredibly brutal repercussions.  See, e.g.From Gamergate to Cecil the lion:  internet mob justice is out of controlVoxavailable at  They’ve made salient points about the need for due process and the proportional response inherent in most (though not all) of the sentencing laws that society has chosen to enact.  And they’ve noted that the internet and other instantaneous, horizontal communications technology make a mob mentality much more likely to arise and much easier to execute.

But I think there’s another philosophical/legal aspect to the recent events.  The online community’s quick responsiveness to stimuli, combined with the voracious response and life-altering consequences that can be inflicted strike me as violating some civilian, non-governmental, philosophical principle of lenity.  The principle of lenity states that when a law can be interpreted either to establish an accused’s innocence or his guilt, it must be interpreted to establish his innocence.  What the principle of lenity is fundamentally designed to do is provide advanced notice — you shouldn’t be thrown into jail for an act that you couldn’t have reasonably anticipated would be criminal.

Now, the principle only applies against the government.  But there seems to be some equivalent notion in society; it has usually seemed wrong to suddenly move the goalposts on people with regards to what behavior is acceptable and what behavior is punished, particularly severely.

It seems, however, that this recent phenomena is upending the principle to an extent.  Cass Sunstein has described what’s happening as a “norm cascade:” the idea that a new norm can quickly emerge and overtake society at a pace much more rapid than norms usually overtake society.  See Cass Sunstein, Social Norms and Social Rulesavailable at  Sunstein invoked the norm cascade principle recently to describe the incredibly rapid shift in public opinion on the Confederate battle flag.  Though many or most people already opposed the flag, it was to some extent a viable issue on which two opinions existed in organized society.  That’s largely changed, and it’s changed in the short time since the Emmanuel Church massacre.

These cases are so hard to lend any sympathy to:  poaching is horrifying, and support for the Confederate flag is a pretty great indicator that you’re somebody I don’t want to key my moral compass to.  But other, slightly grayer examples illustrate the danger.  The Mozilla CEO was ousted in 2012 for having supported California’s Prop 8 (opposing same-sex marriage) in 2008, even though President Obama and Secretary Clinton likewise opposed same-sex marriage at that point.  Gay marriage has been another classic norm cascade–in the window of ten years, it went from a useful wedge issue for the right, to somewhat widely accepted, to a mandate of federal constitutional law.

Ultimately, the issue here isn’t just mob justice, or the quickness of the internet.  It’s the extreme punishment of the first few people that are on the wrong side of a norm cascade.  The behaviors for which they are punished may be recognized as questionable, but in a short amount of time, they shift from questionable to capital crimes.  We have to ask whether any philosophical or social lenity is due when a cascade catches someone as it’s rolling down a hill.

Norm Cascades and the Principle of Lenity