Believe it or not, mathematical techniques and computational power have increased in the past hundreds of years, not to mention the digitization of everything.

Privacy issues that weren’t possible before due to cost are now pennies to exploit. Also keep in mind as it points out people were using census data to drive gerrymandering efforts, so these attacks are real and have been going on for a long time.

> but there were no privacy features before. so we’re actually still much better off than we were for hundreds of years before this.

One notable thing we have today that we didn't have 100 years ago is a computer. Before, you could reasonably assume that recreating individual records wasn't feasible, at least not on a large scale. You can't assume that now. A 4 digit password was safe for hundreds of years, but it would be a security lability today for the same reason.

The concerns here, like most concerns about privacy, are hyperbolic hypothetical hypochondria, until they’re not.

For decades we were encrypting our communications with rsa, surely nothing is wrong with it?

Computers and improvements in data science/machine learning are basically the entire explanation. A LOT of the techniques that we use today to de-anonymize data require computation power not previously available. Even when doable, resources limited scale. Source: statistics degree

(Also, linkage. There are more data sources to cross reference now with the internet and social media and web tracking and hacks - the record footprint of Americans even as recently as the 70s and 80s was dramatically lower!)

As the article clearly states, privacy features have been in the census since 1990. It is just that the previously used privacy feature was not very strong and could be defeated. So it was replaced by a stronger feature in 1920. Before 1990 the census. 1990 was when personal computers were being popularized and the computing power available to individuals exploded and so then it was possible to use computers to separate out individual information from the data the census publishes. So the issue came up then.

No it is not an overblown problem.

As far as I recall they did have some measures in place. Differential privacy just made it a bit more robust.

Arguably the defaults for differential privacy are too robust but that is a different story.