When it comes to mass spying, the best game in town is not CIA or any of the alphabet soup agencies. Private companies and data brokers have been doing data collection on a massive scale, and given their advanced statistical methods, this information can say a lot about a person. In fact, I’d say that what they have is better than what the alphabet soup has, and their data has a lot of implications.
This started when companies like Amazon realized that they can make a profit every step of the way: sell items to customers, sell customers’ data to data brokers. Data brokering has since become much bigger, and so the data collection methods have also become much more extensive. There are many ways to gather mass data, and these are just the ones I can think of off the top of my head: first, many websites straight up sell their data to brokers. This includes many online vendors, all kinds of popular sites (not all of them, but some of them), adult entertainment sites, you name it. If those sites do not sell data, dishonest brokers can and do embed tracking ads on sites that accept them, revealing a user’s entire browsing history. Then of course there are companies like Google, that sell user search histories.