The head of the U.S. intelligence community has issued a warning that personal tech devices are essentially a gateway into the personal lives of anyone using them and that information could be abused at some point to undermine constitutional protections.

The newly declassified report, commissioned by Director of National Intelligence Avril Haines, centers on “commercially available information (CAI)”—data that is accessible to the general public. It cautions that the increasing quantity and sensitivity of CAI is propelled by advancements in digital technology, such as smartphone location-tracking and the advertising-based business models employed by online companies selling products and services, the Daily Wire reported.

“Today, in a way that far fewer Americans seem to understand, and even fewer of them can avoid, CAI includes information on nearly everyone that is of a type and level of sensitivity that historically could have been obtained, if at all, only through targeted (and predicated) collection, and that could be used to cause harm to an individual’s reputation, emotional well-being, or physical safety,” the report says.

The report goes on to caution that despite the anonymization of much of the data, there is still a significant risk of identifying the individuals to whom the information relates. The potential for matching people with their sensitive data poses a serious risk, as highlighted in the report.

“Without proper controls, CAI can be misused to cause substantial harm, embarrassment, and inconvenience to U.S. persons,” the report cautioned.

It added that “under the U.S. Constitution, federal statutes, and internal procedures of the intelligence community, CAI is generally less strictly regulated than other forms of information acquired by the IC, principally because it is publicly available.”

Yet, the report warned, times have changed.

“In our view, however, changes in CAI have considerably undermined the historical policy rationale for treating [publicly available information] categorically as non-sensitive information, that the Intelligence Community can use without significantly affecting the privacy and civil liberties of U.S. persons,” the report said. “In the wrong hands, sensitive insights gained through CAI could facilitate blackmail, stalking, harassment, and public shaming.”

“The government would never have been permitted to compel billions of people to carry location tracking devices on their persons at all times, to log and track most of their social interactions, or to keep flawless records of all their reading habits,” it went on to say.

“Yet smartphones, connected cars, web tracking technologies, the Internet of Things, and other innovations have had this effect without government participation. While the IC cannot willingly blind itself to this information, it must appreciate how unfettered access to CAI increases its power in ways that may exceed our constitutional traditions or other societal expectations,” it adds.