Final answer:
The Netflix Prize privacy scandal is an example of reidentification through multiple datasets.
Step-by-step explanation:
The Netflix Prize was a competition hosted by Netflix in 2006 that aimed to improve its movie recommendation system. To achieve this, Netflix released a large dataset of movie ratings that contained about 100 million ratings given by about 500,000 users. The dataset was released publicly, and participants were challenged to create an algorithm that could predict how a specific user might rate a movie that they had not yet watched. The algorithm that made the most accurate predictions was then awarded a grand prize of $1 million.
This privacy breach raised many concerns about the privacy risks associated with releasing large datasets, even if the datasets are anonymized. The Netflix Prize scandal highlighted the need for more robust privacy protections to ensure that personal information is adequately protected.