What is "individualized" suspicion?

An interesting issue raised by Kansas v. Glover.

Over at Prawfs, Richard Re has a post on Kansas v. Glover and the need for "individualized" evidence in applying the reasonable suspicion test.  Glover, you may recall, is the case on whether the government has reasonable suspicion to stop a car being driven on the road that is owned by a person with a suspended license.  Richard suggests that the stop in Glover is problematic less because there isn't enough suspicion but because the suspicion is not sufficiently individualized.

I disagree, and I thought it might be worth explaining why.

It seems to me that the stop in Glover is quite individualized.  An officer observed a specific car on the road.  Under state law, the car must have a visible license plate that uniquely identifies the car.  And the government keeps a database linking the car to its owner, as well as another database linking the owner to his driving record.  As a result, the basis for the stop is not just individualized, but about a single individual. The unique license plate is linked to a single owner, and the single owner's specific and individual license status is the reason for the cause.  Assuming that this is enough suspicion -- that is, assuming the inference that a car is being driven by its owner is sufficiently reliable to create the needed cause -- it seems to me that the suspicion is meaningfully individualized.

I gather Richard disagrees because he is looking at a smaller subset.  In my analysis above, I treated the general category as "cars on the road."  I then saw the basis for individualization as "a positive 'hit' indicating that the owner of that car has a suspended license."  In contrast, I gather Richard treats the general category as "cars on the road that have returned a positive 'hit' indicating that the owner of that car has a suspended license." He then looks for a basis of individualization within that category, and he sees none.

One lesson to draw from this difference is that individualization is inherently relative.  We say evidence is "individualized" when we have reason to see it as different from the reference group.  But what's our reference group?  You can always draw that narrowly or broadly.

But is the Fourth Amendment so unmoored?  Just off the top of my head, I wouldn't think so.  Here are some tentative thoughts, as this is an interesting issue worth pondering that I don't yet have the firmest sense of on the merits.

It seems to me that the requirement that reasonable suspicion must be individualized is mostly about evidence that explains why the police picked that person or thing to search or seize and why not a different one.  As long as there is enough amount of suspicion, I don't see, contra Richard, a requirement of individualization beyond that explanation.

Take the Harvard dorm hypothetical in which an officer submits a warrant application consisting solely of two things: first, a study that Harvard dorm rooms are likely to contain illegal drugs; and second, a request to search a particular Harvard dorm room.  In that hypothetical, the suspicion is not individualized because the magistrate has no idea why the police picked that particular room and not one of the many other rooms.  We intuit there must be an explanation for why they picked that one room.  And we become instinctively cautious about whether there is cause because we sense that the government isn't  telling us the whole story of the real reason they are searching that room.

In Glover, by contrast, I'm not aware of a concern as to why the officer picked that particular car.   At least as litigated, we don't have reason to think the officer knew lots of cars had owners with suspended licenses and that the officer had some suspicious reason to pick that one.  So I tend to think that, if the court sees the amount of suspicion as sufficient, the suspicion is individualized by the specific evidence that this particular car was the one whose owner had a suspended license.