Gov. Rendell owes the public far more than just the impassioned, shamefaced apologies he served up this week for his administration's boneheaded tracking of legitimate citizen protest groups as if they posed an actual terrorist threat.

Nothing less than a full, independent investigation followed by a housecleaning will clear the air about this bungled effort supposedly designed to protect the state's "critical infrastructure."

So far, though, Rendell merely has apologized, canceled a six-figure no-bid contract with consultants paid to produce the alerts, and ordered an in-house inquiry. And no heads will roll.

At the state Office of Homeland Security, which ran the program under the Pennsylvania Emergency Management Agency (PEMA), director James F. Powers Jr. - a 30-year military veteran - won't even get a timeout for circulating the useless security alerts. Why? Rendell says there was "collective responsibility" within the agencies for the mishap, and for handing out a no-bid $103,000 contract to the consultants, the Philadelphia-based Institute on Terrorism Research and Response.

Even from a lame-duck administration, a tougher response is required - if only to provide lessons for the next administration so that the state's homeland-security efforts don't go astray again.

The governor himself said the state's circulation of so-called intelligence alerts to law enforcement and private-sector groups about the nonviolent activists - including supporters of Rendell's education agenda - ran roughshod over constitutional rights.

The initiative certainly "smacks of J. Edgar Hoover" paranoia, as noted by Witold Walczak, legal director for the state chapter of the American Civil Liberties Union. Even if no one in law enforcement acted on the alerts, Walczak is right that merely "raising questions about a group or a person can cause harm."

The overall chilling effect on free speech and dissent is just as troubling. Rendell pounded his fist the other day, and declared that "protesting against an idea, a principle, a process, is not a real threat against infrastructure." The fact remains, though, that his administration pursued a policy that sent exactly that message.

Particularly alarming was the targeting of groups that oppose drilling in the Marcellus Shale, which calls into question the state's ability to regulate drillers.

While there have been no credible threats against natural-gas wells, industry-caused mishaps would seem to pose the greatest risk. But homeland-security boss Powers, in a leaked e-mail, stated that the alerts were part of a plan to offer "support to the . . . natural gas stakeholders while not feeding those groups fomenting dissent against those same companies." That sounds like someone running political interference for an industry facing legitimate scrutiny over pollution and whether it's paying its fair share in taxes.

Republican state lawmakers may be right that the General Assembly needs to hold hearings. Activists considering lawsuits may sue to get answers in court, too. But independent inquiries by the state Attorney General and Auditor General Offices, or federal authorities, would be the surest way to hold the right people accountable for this misguided venture.