You've probably read the Philip K. Dick book, Minority Report, or saw the hit movie of the same name. He wrote it in 1956. I seriously doubt that he expected something like it to become a reality.

For two decades, police departments have used computers to identify times and places where crimes are more likely to occur, guiding the deployment of officers and detectives. Now they’re going another step: using vast data sets to identify individuals who are criminally inclined. They’re doing this with varying levels of transparency and scientific testing. A system called Beware, for example, is capable of rating citizens of Fresno, California, as posing a high, medium or low level of threat. Press accounts say the system amasses data not only on past crimes but on web searches, property records and social networking posts.
Critics are warning that the new technology had been rushed into use without enough public discussion. One question is precisely how the software works -- it's the manufacturer's trade secret. Another is whether there’s scientific evidence that such technology works as advertised.

All sorts of warning lights go off from this, most of them involve how the software is designed. For instance...

They did not use race, though Berk said the system isn’t completely race blind because some inferences about race can be drawn from a person’s zip code.

Even if race isn't included in their algorithm (and we don't know if it is or not), what does this say about discriminating against poor people in general?

“Predictive policing used to be the future, and now it is the present.”
- Police Officer William Bratton

The next question is: how is this being used today?
The LA City Council is a very Big Brotherish use for PreCrime.

Los Angeles is considering sending “Dear John” letters to the homes of men who solicit prostitutes hoping the mail will be opened by mothers, girlfriends or wives.
Privacy advocates are slamming the idea. The plan would use automated license plate readers to generate the letters, which would be aimed at shaming “Johns,” the Los Angeles Daily News reported.

About a dozen American cities — including Los Angeles as well as Santa Cruz, Calif., Atlanta, and Tacoma, Wash. — are using PredPol. Los Angeles PD has already rolled it out to 14 of its 21 divisions.

Microsoft is also getting into the business.
Mobile phones appear to be the most valuable tool in PreCrime.

Obviously The GWOT hysteria is a gold mine for PreCrime experimentation.
The way the No-Fly List is carried out is the very definition of PreCrime.

In a little-noticed filing before an Oregon federal judge, the US Justice Department and the FBI conceded that stopping US and other citizens from travelling on airplanes is a matter of “predictive assessments about potential threats”, the government asserted in May.

And as for those terrorists that get arrested? Well, you have to adjust the definition of the word "terrorist" a bit.

In 2009, Sadequee was tried, convicted, and sentenced to a 17-year federal sentence. But even after receiving that harsh sentence, the irksome fact remained that Sadequee had never actually committed an act of terrorism. The allegations against him amounted to statements and translations he had made online as a teenager. At his trial, Sadequee said that these online activities were “just talk,” and were never intended to manifest in an act of violence....
“It goes down to the issue of what you do when you come across a teenager making provocative statements online. As a society, is it our responsibility to string them along and send them to jail?”

So where does this inevitably lead?
Denmark is already going there.

In 2014, some 2,383 people were preventatively detained. The numbers for 2015 have not been tallied up yet, but the upward trend looks set to continue.
“The trend in the numbers and court cases in which demonstrators or others have been preventatively detained suggest that the police’s interpretation of the law does not place enough emphasis on civil liberties, including the freedom of expression and assembly,” Justisia head Jacob Mchangama told Berlingske.

China is going all in on PreCrime.

The Communist Party has directed one of the country’s largest state-run defense contractors, China Electronics Technology Group, to develop software to collate data on jobs, hobbies, consumption habits, and other behavior of ordinary citizens to predict terrorist acts before they occur. “It’s very crucial to examine the cause after an act of terror,” Wu Manqing, the chief engineer for the military contractor, told reporters at a conference in December. “But what is more important is to predict the upcoming activities.”
The program is unprecedented because there are no safeguards from privacy protection laws and minimal pushback from civil liberty advocates and companies, says Lokman Tsui, an assistant professor at the School of Journalism and Communication at the Chinese University of Hong Kong, who has advised Google on freedom of expression and the Internet. The project also takes advantage of an existing vast network of neighborhood informants assigned by the Communist Party to monitor everything from family planning violations to unorthodox behavior. A draft cybersecurity law unveiled in July grants the government almost unbridled access to user data in the name of national security. “If neither legal restrictions nor unfettered political debate about Big Brother surveillance is a factor for a regime, then there are many different sorts of data that could be collated and cross-referenced to help identify possible terrorists or subversives,” says Paul Pillar, a nonresident fellow at the Brookings Institution.

We shouldn't let China be the trendsetter that our government feels it needs to follow.