Five years ago, Congress killed an experimental Pentagon antiterrorism program meant to vacuum up electronic data about people in the U.S. to search for suspicious patterns. Opponents called it too broad an intrusion on Americans’ privacy, even after the Sept. 11 terrorist attacks.

But the data-sifting effort didn’t disappear. The National Security Agency, once confined to foreign surveillance, has been building essentially the same system.

Several thousand law enforcement agencies are creating the foundation of a domestic intelligence system through computer networks that analyze vast amounts of police information to fight crime and root out terror plots.

As federal authorities struggled to meet information-sharing mandates after the Sept. 11, 2001, terrorist attacks, police agencies from Alaska and California to the Washington region poured millions of criminal and investigative records into shared digital repositories called data warehouses, giving investigators and analysts new power to discern links among people, patterns of behavior and other hidden clues.

The FBI has awarded a nearly $1 billion contract to Lockheed Martin to help create a massive computer database of people’s physical characteristics as part of an effort to better identify criminals and terrorists.

The overall deal is worth between $850 million to $1 billion and could run as long as 10 years, said Thomas Bush, the FBI’s assistant director of the Criminal Justice Information Services Division.

_Microchips with antennas will be embedded in virtually everything you buy, wear, drive and read, allowing retailers and law enforcement to track consumer items — and, by extension, consumers — wherever they go, from a distance.

_A seamless, global network of electronic “sniffers” will scan radio tags in myriad public settings, identifying people and their tastes instantly so that customized ads, “live spam,” may be beamed at them.

_In “Smart Homes,” sensors built into walls, floors and appliances will inventory possessions, record eating habits, monitor medicine cabinets — all the while, silently reporting data to marketers eager for a peek into the occupants’ private lives.

A growing number of sheriff’s departments are using iris scans to identify sex offenders, runaways, abducted children and wandering Alzheimer’s patients.

More than 2,100 departments in 27 states are taking digital pictures of eyes and storing the information in databases that can be searched later to identify a missing person or someone who uses a fake name, says Sean Mullin, president of BI{+2} Technologies, which sells the devices.

Morse says his company will deliver test devices to the Defense Department next year that will allow it to scan a crowd and store iris data for many people at once.