Figure 2 - Washington, D.C., taken March 31, 2006 by IKONOS, courtesy of GeoEye.


Reasonable Expectations in a Google Earth World

A U.S. citizen’s right to privacy—to freedom from government observation—has become increasingly important in the geospatial community. Last year, the Department of Homeland Security (DHS) announced the creation of the National Applications Office (NAO).
Kevin Pomfret, Esq.
Cantor Arkema PC
Richmond, Va.
One of the stated goals of the NAO is to provide federal, state and local law enforcement officials with access to the nation’s classified reconnaissance systems. However, Republicans and Democrats on Capitol Hill expressed such serious concern about the program’s privacy and civil implications that DHS has placed that portion of the NAO on hold.

More recently, Deputy Director of National Intelligence Donald Kerr, in remarks made at GEOINT 2007, suggested that it is time for Americans to rethink their concept of privacy. Although his remarks were meant for a broader audience, it was not surprising that he gave them before a meeting of geospatial professionals.


Unfortunately, privacy is difficult to define in a legal context, as by its very nature it is personal and subjective. In addition, the law has not kept pace with improvements in technology to collect, process, analyze and distribute personal data. As a result, there are few clear legal lines as to what constitutes an improper infringement of privacy by the government. Therefore, in order to get a sense as to how the concept of privacy applies to today’s geospatial technology, it is important to understand how the law has been applied in similar matters.

Privacy and Remote Sensing

One of the primary sources for the protection of privacy in the United States is the Fourth Amendment of the Constitution. The Fourth Amendment requires the government to obtain a warrant based upon probable cause before conducting a search of an individual, a home or a place where an individual might have "a reasonable expectation of privacy." To date, there have been no reported cases involving the use of satellite technology to conduct an improper search by the government.

However, there have been a few important cases that have addressed "a reasonable expectation of privacy" in a remote sensing context. For example, in Dow Chemical Co. v. U.S., decided in 1986, Dow claimed that the Environmental Protection Agency (EPA) violated Dow’s Fourth Amendment rights when it hired a commercial aerial photographer to photograph one of Dow’s facilities without first obtaining a warrant. The photographer used a standard mapping camera and flew within lawful airspace. The Supreme Court held that even though Dow had security walls around its complex, it did not have a reasonable expectation of privacy with respect to what was not covered behind the walls because it was "open to the view and observation of persons in aircraft lawfully in the public airspace immediately above. . ." It is worth noting however, that the court left open the question as to whether "surveillance of private property by using highly sophisticated surveillance equipment not generally available to the public, such as satellite technology, might be constitutionally proscribed absent a warrant."

Similarly, in California v. Ciraolo, also decided in 1986, two police officers had hired a plane to fly over a private house to see if they could see signs of marijuana being grown. The house was otherwise surrounded by a fence. Based upon visual observation of marijuana plants, the police obtained a warrant to search the house and subsequently seized the plants. Ciraolo’s attorney argued that the flyover was an unreasonable search and seizure, because it violated Ciraolo’s reasonable expectation of privacy with respect to his back yard. However, a majority of the Supreme Court disagreed, finding in part that "…in an age where private and commercial flight in the public airways is routine, it is unreasonable for respondent to expect that his marijuana plants were constitutionally protected from being observed with the naked eye from an altitude of 1,000 feet."

A few years later, in Florida v. Riley, the Supreme Court was faced with a similar set of facts. However, in this case, a sheriff used a helicopter instead of a plane to fly over a house and conduct a visual search. Based upon what he saw in openings in a greenhouse roof and through its open sides, the official obtained a warrant and in the search found marijuana. Riley’s attorney argued that the helicopter overflight violated Riley’s constitutional rights in part because the helicopter did not fly at the required altitude for aircraft. However, the majority of the Supreme Court found that because the helicopter was within the FAA altitude requirements for a helicopter, that Riley’s expectation of privacy was unreasonable as he did not completely cover the marijuana from view.

Justice O’Connor’s concurring opinion helps show how complex this analysis can be. She stated that the majority relied too heavily on whether the helicopter was flying in compliance with FAA regulations. Instead, she argued that a reasonable expectation of privacy was "whether it was in the public airway at an altitude at which members of the public travel with sufficient regularity that respondent’s expectation was not one that society would find reasonable." She added that observations from helicopters circling over a home may be sufficiently rare that police surveillance from such an altitude would violate a reasonable expectation of privacy, despite compliance with FAA regulations.

In Kyllo v. U.S., decided in 1989, the issue before the Supreme Court was whether the use of a thermal-imaging device aimed at a private home from a public street to detect relative amounts of heat constitutes a "search" within the meaning of the Fourth Amendment. In delivering the opinion of the court, Justice Scalia stated that "…where, as here, the government uses a device that is not in general public use, to explore details of the home that would previously have been unknowable without physical intrusion, the surveillance is a ‘search’ and is presumptively unreasonable without a warrant." In contrast, the dissent argued that it was not a search of the home, as it only detected heat that radiated out of the home, and not the home itself. Therefore, there would have been no reasonable expectation of privacy.

It is clear from the cases above that there is a fine line when determining when the using of remote sensors by the government for law enforcement purposes is a violation of privacy. However, these decisions suggest that, given the current widespread availability of satellite imagery, its use by law enforcement without a warrant would not violate a citizen’s Fourth Amendment rights. It would simply be hard to argue that anyone in the United States has a reasonable expectation of privacy from an electro-optical imaging satellite, unless the sensor was of a quality or type that was much better than commercially available. (In that case, law enforcement officials would be better off using imagery from commercial satellites if at all possible.) On the other hand, the Kyllo decision suggests that the use of other sensors on satellites without first obtaining a warrant would be unconstitutional if of a type and quality that are not currently available or known to the general public.

The Fourth Amendment and "Tracking"

The Supreme Court has also stated that "tracking" an individual through the use of technology can also violate that person’s Fourth Amendment rights. However, case law indicates that defining when an individual’s privacy has been violated is difficult. Moreover, as the technology has changed, disagreements have arisen between various courts as to what is permissible.

In United States v. Knotts, decided in 1983, the police had placed a radio transmitter inside a container of chemicals used to make illicit drugs and sold the container to a defendant. The police then tracked the defendant through public streets using the transmitter, to Knotts’ home. After obtaining a warrant to search Knotts’ premises, based upon information learned by following the defendant and from monitoring the house, the police found illegal drugs. Knotts’ attorney claimed that tracking the defendant’s movements to his house through the transmitter without obtaining a warrant violated his Fourth Amendment rights.

Figure 1 - Manhattan, N.Y., taken May 25, 2007 by IKONOS, courtesy of GeoEye.

The Supreme Court disagreed, stating in part that "…a person traveling in an automobile on public thoroughfares has no reasonable expectation of privacy in his movements . . ." It added, "…nothing in the Fourth Amendment prohibited the police from augmenting the sensory facilities bestowed upon them at birth with such enhancements as science and technology afforded them in this case."

However, in 1984 the Supreme Court drew a line in the use of tracking movements in United States v. Karo. In Karo, the police not only used the transmitter to follow movements in public places, but to identify that illicit containers were located in various private residences. Based upon this information, they obtained a warrant and searched one of the premises, where cocaine was found. The court ruled that the transmitter could not be used to identify activities or what was in a house or private facility because that violated an individual’s reasonable expectation of privacy with respect to such house.

More recently, there have been a number of cases concerning the attempted use by law enforcement to track an individual’s real-time location based upon cell site data under the Stored Communications Act. Unfortunately, case law has not been consistent.

The Stored Communications Act (SCA) authorizes law enforcement to seek from the courts permission to obtain stored communications or transaction records in the hands of third-party providers. Section 2703(c) of the SCA permits the government to collect "a record or other information pertaining to a subscriber to or a customer of such service." Section 2703(d) states that in order to receive the data, the government needs to show only "specific and articulatible facts showing . . . reasonable grounds to believe that . . . the records or other information sought, are relevant and material to an ongoing criminal investigation." This reasonable grounds standard is considerably lower than probable cause provided in the Fourth Amendment.

The cases of tracking a person’s real-time location have involved instances when the government has tried to obtain real time cell site data from telecommunications companies, citing Section 2703(c), under the reasonable grounds standard of Section 2703(d). In many such cases, the court has found that the "reasonable grounds" standard was insufficient because of Fourth Amendment protections. Therefore, the government needed to have probable cause in order to compel disclosure of the cell site data. [See for example, In the Matter of the Application of the United States of America For An Order Authorizing the Release Of Prospective Cell Site Information, 407 F. Supp. 2d 134 (D.D.C. 2006); In the Matter of An Application Of the United States For A Order Authorizing Pen Register And A Trap And Trace Device And Release Of Subscriber Information And/Or Cell Site Information, 384 F. Supp. 2d 562); In re Application for Pen Register and Trap/Device with Cell Site Location Authority, 396 F. Supp. 2d 747 (S.D. Tex. 2005).]

However, not all courts have reached this conclusion. For example, in the case of In re Application for an Order Authorizing the Extension and Use of a Pen Register Device 2007 WL 397129 (E.D. Cal. Feb. 1, 2007) and In re Application of the United States, 411 F. Supp. 2d 678 (W.D. La. 2006), the courts allowed the government to obtain real time cell site data under the Section 2703(d) standard.

To further complicate the law in this area, a court recently held that law enforcement does not need probable cause to collect historic location data on an individual: In re Applications to the United States of America For Orders Pursuant to Title 18, United States Code Section 2703(d) (MBD-07-10192-RGS, September 17, 2007). In that case, the government was seeking a court order to require companies to release historical cell site information. The U.S. District Court judge found that a person’s historical movements did not justify a reasonable expectation of privacy. Therefore, all the government needed to show was that such information was relevant to an ongoing investigation.

Rapid improvements in spatial technology have challenged the legal system in a number of different ways. Privacy is certainly one of the most difficult issues. The legal system has and will continue to struggle to define privacy in a spatial context, particularly as commercial applications for satellite imagery, GPS, RFID, GIS and other technologies grow. In the meantime, courts will seek to protect privacy rights by analyzing laws that are not easily applied to the current technology. Nevertheless, one can get a sense as to the legal framework as well as the potential issues by examining how privacy law has been interpreted and applied to other technologies.

It is also important to note that these issues are not important only to constitutional scholars. For example, a number of telecommunications companies are being criticized for failing to protect their customers’ privacy by turning over telephone records to the government. The White House has attempted to provide immunity to those companies, but to date Congress has not agreed to add such provisions to legislation. Companies that collect spatial data should monitor the legislation and the cases closely as they may affect them in the near future.

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