New England is being used as a guinea pig for a new profiling program that hopes to spot potential terrorists before they board an airplane.

Airports in Portland, Bangor, Boston and Rhode Island have implemented a pilot program that uses specially trained security agents to spot “suspicious” behavior by travelers. Called SPOT – Screening Passengers by Observation Techniques – the program teaches screeners how to detect the telltale signs of stress, dishonesty or fear.

The idea isn’t new. Israel has used similar techniques to screen airline passengers for years, and police officers in the country are trained to determine if someone is lying by looking for particular physical manifestations of deception.

The American Civil Liberties Union opposes the Transportation Security Administration program, saying that it opens the door to racial profiling and submits passengers to extra scrutiny based on subjective criteria.

We see the potential for misuse. Cultural differences and stress created by any number of outside factors could cause screeners to unnecessarily target people with no ill intent. At the same time, the potential for an added layer of security makes the program worth evaluating.

Our bigger concern is that the SPOT screening, which is less expensive than other methods, might be put in place to save money while other gaps in security are allowed to go unfilled.

Today, more than four years after the attacks of Sept. 11, most of the cargo carried aboard commercial airlines is not screened. While passengers are forced to peel off their belts, take off their watches and shoes and – at least in Portland and Bangor – pass a suspicious behavior test, tons of packages go unchecked.

That’s enough to make us nervous. Maybe even nervous enough to catch the attention of a SPOT inspector.