The Port Authority of New York and New Jersey was under fire. It was 2012 and the agency had just hiked tolls on area bridges and tunnels. Inside a hearing room on Capitol Hill, the Port Authority's deputy chief, Bill Baroni, was absorbing withering criticism from Sen. Frank Lautenberg, the late New Jersey Democrat.

Lautenberg carried a reputation as the political nemesis of New Jersey Gov. Chris Christie, a Republican who had appointed Baroni to his perch. Baroni swiftly attacked the senator: How could Lautenberg justify his opposition to raising tolls when he had himself enjoyed free passage across area bridges and tunnels?

"Respectfully, Senator, you only started paying tolls recently," Baroni said, according to a transcript of the exchange. "In fact, I have a copy of your free E-ZPass," he continued, holding up a physical copy of the toll pass Lautenberg had received as a benefit from his tenure as a Port Authority commissioner. "You took 284 trips for free in the last 2 years you had a pass."

Within days, Christie himself disclosed further detailed information about Lautenberg’s private travel records. At a press conference, he alleged that the senator didn't "pay for parking at Port Authority facilities" and said Lautenberg went "through the tunnel to New York three or four times a week in 2005 and 2006."

A year later, the Christie administration's relationship with the Port Authority would burst into public view as the centerpiece of a scandal known as Bridgegate, in which the governor's staff allegedly conspired with the transportation overseer to close lanes leading to the George Washington Bridge, generating traffic jams as punishment for communities whose elected officials had not amply supported the governor.

Christie has repeatedly dismissed the episode as a rogue decision by his staff, maintaining that he was not consulted and would never have authorized such a stunt. But the exchange with Lautenberg and Christie's direct citation of his personal travel records underscore the degree to which his administration was already using the Port Authority as an instrument in his famously hard-nosed brand of politics.

At the time, the discussion of Lautenberg's travel history seemed like just another prop in the confrontational style of politics that dominates New Jersey. But the data that Baroni and Christie unleashed in assailing Lautenberg was not publicly available. Indeed, in a recent letter responding to an open records request, the Port Authority deemed those very same travel records off-limits to the public. Tim Feeney, a spokesman for the New Jersey Turnpike Authority, confirmed to International Business Times that under New Jersey law, E-ZPass records can be obtained only with a civil court order or criminal subpoena.

Christie’s office rebuffed an open records request from IBTimes seeking the data about Lautenberg's E-ZPass usage that the governor had himself detailed at a 2012 press conference, asserting that it had no such records. Neither Baroni, Christie nor the Port Authority responded to questions about how they had been able to obtain such details.

On Tuesday, the U.S. Attorney in New Jersey issued a subpoena to members of the state legislature seeking records related to Baroni’s testimony at a 2013 hearing on the Bridgegate scandal. At that hearing, Baroni disclosed that he possessed E-ZPass customer data showing the traffic histories of constituents of state lawmakers who were interrogating him.

Experts tell IBTimes that the disclosure of E-ZPass records appears to have violated state law protecting the privacy of drivers and also raises serious questions about the degree to which government agencies can keep tabs on the comings and goings of citizens.

“This is the kind of thing that reminds everyone why privacy is important: Information is power and always raises the temptation for abuse,” said Jay Stanley, a privacy expert at the American Civil Liberties Union. “Any kind of data that reveals our locations and travels is potentially very powerful stuff that lends itself to abuse for Nixonian dirty tricks, embarrassment of rivals or leverage over critics. If officials feel comfortable using information against a prominent person like Frank Lautenberg, what is the ordinary person supposed to think about how data could be used against them?”

The apparent use of private traffic data as a tool in New Jersey's political jockeying underscores concerns about whether such information is being used in less public ways by government officials who have access to the data. Such concerns are particularly acute in an era in which technology has made transit and communications histories easily searchable to those with access to the pertinent data.

In New York, the city's database of taxi records this year allowed software programmers to identify the movements of celebrities and other individuals throughout the city. In other cities across the country, police departments are vacuuming up license plate location data, allowing officials to chart the movement of individuals' automobiles.

In Washington, three U.S. senators sent letters to ridesharing companies Uber and Lyft raising questions about whether those firms are improperly compiling their travel data to track journalists they don’t like. Other lawmakers have raised questions about whether the National Security Agency is using telephone metadata to surveil members of Congress. A recently disclosed government report showed that an NSA analyst “searched her spouse’s personal telephone directory without his knowledge to obtain names and telephone numbers for targeting.”

Some states have already enacted protections designed to create a firewall between politicians and citizens’ personal information amassed by the government. In Pennsylvania, transportation officials say that “by state law, E-ZPass data is strictly protected, and it can only be obtained through subpoena by law-enforcement agencies during a criminal investigation.”

Utah in 2013 passed a law limiting the amount of time government agencies may keep citizens’ travel information gleaned from high-speed license plate readers. Five other states have similar laws restricting governments from compiling citizens’ travel data for fear that the information will be improperly used.

New Jersey law says toll records cannot be released to any person or governmental agency unless they have a subpoena or court order. E-ZPass terms and conditions declare that "account information will not be disclosed to third parties without [customer] consent except as required or permitted by law."

Despite those protections, Lautenberg's records became fodder in Christie's attempts to diminish the senator. At the 2012 press conference, Christie cited E-ZPass records to question whether the senator spent enough time attending to his state's business.

“What was he doing going through the tunnel or over the bridge 284 times for free in '05 and '06?” Christie asked. “Was he ever in Washington? And when he wasn't in Washington what was he doing in New York? Did he ever spend any time in New Jersey?” Citing the travel records, Christie called Lautenberg "an embarrassment to the state."

Even before Baroni first publicized Lautenberg's toll history, such accounts were apparently being shopped quietly to the press as a means of embarrassing the senator. A source who worked for Lautenberg at the time confirmed that his office received a media inquiry about his travel records several months before Baroni's appearance at the 2012 hearing. The source said that led Lautenberg aides to conclude that Christie or the Port Authority was trying to use the private records to plant an unflattering story about the senator.

After Baroni testified about Bridgegate in 2013, Christie's campaign manager, Bill Stepien, sent a text message to him saying: “I know it’s not a fun topic, and not nearly as fun as beating up on Frank Lautenberg, but you did great, and I wanted to thank you."

The New York Times  reported that "aides to Mr. Christie cheered Mr. Baroni’s performance" at the Lautenberg hearing. The Times also reported that Baroni "sent word through mutual friends to people on Mr. Lautenberg’s staff that he regretted the scene" in which he divulged the travel records, but that "the instructions, he explained, had come from Trenton."

In 2014, Andrew Perez, then a fellow at the Huffington Post, filed an open records request with Port Authority officials asking for all documents related to Lautenberg’s enrollment in the E-ZPass program, as well as any communications at the Port Authority about those records. He also asked for the Port Authority’s internal policy on employees accessing citizens’ private travel data.

“I figured that since Baroni and the governor already disclosed these records, they should be provided to me, and I expected the Port Authority should have a detailed policy on who at the Port Authority was allowed to access E-ZPass records,” Perez told IBTimes.

Instead, the Port Authority rejected his request, saying that “certain records are exempt from disclosure” under the agency's policy of not releasing documents that "constitute an unwarranted invasion of personal privacy of an individual." Along with that rejection notice, the agency did release a document promising E-ZPass customers “nondisclosure” of their records.

"If we now know the Port Authority says these records cannot be divulged, then the big question is: How did Mr. Baroni and Gov. Christie get access to them?" said Loretta Weinberg, one of the Democratic state senators who led the New Jersey legislature's investigation into the Bridgegate affair. "The privacy policies appear to have been breached in order to try to embarrass a U.S. senator and browbeat him into not asking tough questions. Not only must the governor answer for this, but his Port Authority commissioners and the Port Authority executive director need to explain how these records were obtained in the first place."

IBTimes asked P.J. Wilkins, the executive director of E-ZPass, whether public officials like governors have the right to review customers’ travel records without a subpoena or court order. He answered: “In all my years of [working at] E-ZPass, I have never seen that happen.” He said that without a subpoena, “I don’t know why somebody would be given that kind of access to these records.”

Sen. Al Franken, a Democrat who has called for Uber and Lyft to more explicitly protect customers' travel information, told IBTimes that the E-ZPass episode spotlights the need for tough privacy protections for personal data that is given to the government.

"Public agencies -- like private companies -- are often in a position to collect personal data, and agencies have recognized responsibilities when it comes to protecting this information," the senator said. "Indeed, when you consider the potential for politically motivated uses or disclosures of government data, the importance of these responsibilities becomes especially clear. It is crucial that government agencies take adequate steps to prevent misuse by either outsiders or their own employees."