The answer, according to a new research paper, is about a week, when the data portrait of a person becomes sufficiently detailed to qualify as an “unreasonable search” and a potential violation of an individual’s Fourth Amendment rights.
The research paper, a collaboration of computer scientists and lawyers, wades into the debate over the legal and policing implications of modern data collection and analysis technology. It explores what in legal circles is called the “mosaic theory” of the Fourth Amendment, which essentially states that when linked and analyzed by software, a much richer picture emerges from combined information than from discrete data points.
“It’s not the direct observation,” said Steven M. Bellovin, one of the paper’s co-authors and a computer science professor at Columbia University, a computer security and privacy expert and a former chief technologist of the Federal Trade Commission. “It’s what can be inferred.”