Because it costs practically nothing. If the cost is zero and the expected value is greater than zero, then no matter how little value it has it's still rationa

Because it costs practically nothing. If the cost is zero and the expected value is greater than zero, then no matter how little value it has it's still rational to collect it. The problem is that the individual bears a very small risk of something very bad happening: "consider the hypothetical case of a gay blogger in Moscow who opens a LiveJournal account in 2004, to keep a private diary. In 2007 LiveJournal is sold to a Russian company, and a few years later—to everyone's surpise—homophobia is elevated to state ideology. Now that blogger has to live with a dark pit of fear in his stomach." https://idlewords.com/talks/haunted_by_data.htm https://idlewords.com/talks/haunted_by_data.htm The individual of course gets no benefit from the small chance the company can monetize on this data trove. So even though chances are they aren't harmed at all by this data collection, arguably the expected value of the benefit/harm to the individual is negative (harmful). But that doesn't change the data collector's calculation, of course. That's why government regulation is necessary.