[tpolzer]

One of the oldest (AFAIK) occurrences of this was AOL releasing a data set of "anonymized" search queries in 2006 and it took a about a day for the first person to be deanonymized.

https://www.nytimes.com/2006/08/09/technology/09aol.html

https://techcrunch.com/2006/08/09/first-person-identified-fr...