NEW YORK (CNN/Money) - Federal authorities are adding facial-recognition technology to the arsenal of weapons used to thwart potential terrorist attacks.

The United States Park Police are deploying a facial-recognition surveillance system at the entry point for the ferries that take tourists to Ellis Island and the Statue of Liberty as part of a series of stepped-up security measures at New York City landmarks.

The system, on loan from a company called Visionics Corp., keys in on unique facial characteristics and compares them against a database of known terrorists and other wanted people.

Called "FaceIt ARGUS," the system is being installed in an area at the foot of the boarding planks for the ferries that bring passengers to the landmarks, which the FBI have identified as likely terrorist targets. It will automatically scan all faces passing through the entryway and compare them against a database of terrorists compiled by federal authorities.

Visionics (VSNX: down $0.17 to $10.80, Research, Estimates), which in February agreed to merge with Identix (IDNX: down $0.21 to $7.99, Research, Estimates), a top supplier of fingerprint scanning systems, said signs informing the public that the system is in use will be posted in corresponding areas and that all non-matches will be automatically deleted from the system.

The system will be in use for the Memorial Day holiday weekend, during which large crowds are expected to visit the New York Harbor landmarks, which are operated by the federal government.

Shares of Visionics were trading lower on Nasdaq Thursday afternoon but have risen more than 150 percent since the Sept. 11 terrorist attacks on the United States.

Prior to the attacks, which were carried out in hijacked commercial airliners, the use of facial-recognition surveillance systems had met with public resistance, due to privacy concerns.

But there has been much wider acceptance in the months following the attacks.

Similar systems to the one being used in New York over the weekend currently are in the testing phases at four U.S. airports, including Boston's Logan International, where two of the hijacked Sept. 11 flights originated.

There still remains some controversy about the effectiveness of the systems, and so far the early returns from the airport tests -- which also have been underway at airports in Dallas-Fort Worth, Fresno, Calif. and Palm Beach, Fla. -- have been mixed.