I. Privacy Protections Under the Fourth Amendment
The Fourth Amendment of the Federal Constitution protects the people’s right “to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.” The Supreme Court of the United States recognizes that “[t]he ‘basic purpose of [the Fourth] Amendment’ . . . ‘is to safeguard the privacy and security of individuals against arbitrary invasions by government officials.’” Historically, courts analyzed whether a search was reasonable by determining whether the police obtained the information “‘by physically intruding on a constitutionally protected area.’”
However, whether a search involves a physical trespass is “‘not the sole measure of Fourth Amendment violations.’” In Katz v. United States, the Court went beyond its traditional property-based Fourth Amendment jurisprudence to establish that “the Fourth Amendment protects people, not places.” That decision linked “certain expectations of privacy” to protection from unreasonable searches. As a result of Katz, the Court now holds that police officers violate a person’s Fourth Amendment rights not only through warrantless invasions of traditional property rights, but through intrusions upon that person’s “‘reasonable expectation of privacy’” as well. To determine if someone has a reasonable expectation of privacy, the Court looks to whether that person sought “‘to preserve something as private,’” and if that person’s “expectation of privacy is ‘one that society is prepared to recognize as reasonable[.]’”
II. Privacy Implications from Technological Innovation
Technological innovation has changed societal expectations in numerous ways: consumers expect speedy deliveries from centralized shippers, employers expect remote employees to respond to emails without delay, and universities expect students to own a personal laptop. Naturally, technological innovation similarly occurs in government surveillance tools. Accordingly, the Supreme Court recognizes that “technology has enhanced the Government’s capacity to encroach upon areas normally guarded from inquisitive eyes,” so the Court seeks to secure “that degree of privacy against government that existed when the Fourth Amendment was adopted.”
This interplay between Fourth Amendment searches and advancing technology came to a head in Kyllo v. United States when the Court held that use of a thermal imager to detect “heat radiating from the external surface of [defendant’s] house” constituted a search. The Kyllo Court established that a search occurs when police use “sense-enhancing technology” to obtain “any information regarding the interior of the home that could not otherwise [be] obtained without physical ‘intrusion into a constitutionally protected area[.]’” The majority held that, “[w]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.” This holding drew ire from the dissent, and to date, no court has defined what it means for something to “not [be] in general public use.” Instead, the Court “tread[s] carefully” when “considering new innovations . . . to ensure that [it does] not ‘embarrass the future.’”
III. Modern Technology and “General Public Use”
What constitutes “sense-enhancing technology” not in general public use? Present case law provides almost no guidance on this question. The most recent discussion of the question arose in United States v. Tuggle, in which the Seventh Circuit used a “straightforward application of Kyllo” to find that the government’s “use of pole cameras” did not violate “Fourth Amendment protections” in part because “[t]oday, cameras are in ‘general public use.’” In Tuggle, government officials placed three cameras on public utility poles to monitor the exterior of the defendant’s home without a warrant. The officials continued to monitor the defendant’s home for almost eighteen months after installing the first camera. The cameras provided the investigators with numerous advantages in their investigation, such as around-the-clock recordings, basic lighting to improve overnight footage (although they lacked other enhancements like infrared technology or audio recording faculties), the ability for officers to “remotely zoom, pan, and tilt” while viewing in real-time, and the ability to secretly monitor the defendant’s comings and goings “without conspicuously deploying agents to perform traditional visual or physical surveillance.” The court concluded that cameras are in “‘general public use,’” because “[n]ow more than ever, cameras are ubiquitous, found in the hands and pockets of virtually all Americans[.]” Expanding on cameras’ “ubiquit[y],” the court relied on the fact that the cameras could not “‘penetrate walls or windows so as to hear and record confidential’ information[.]” Rather, they were only used to identify the defendant’s visitors and “what they carried, all things that a theoretical officer could have observed without a camera.”
There are obvious and compelling public safety reasons for giving law enforcement broad discretion over surveillance techniques. Given that criminals have increasing access to advanced technology, which they use to conceal their actions and intentions, law enforcement must also have the means to find and stop them. Still, courts must strike a balance between public safety and individual rights so that law-abiding homeowners and tenants are not left to “‘the mercy of advancing technology[.]’”
Chief Justice Roberts addressed this delicate balance between government surveillance techniques and an individual’s use of advanced technology in Carpenter v. United States. There, the Court dealt with the “Government’s acquisition of wireless carrier cell-site records” which showed the petitioner’s cell phone location “whenever it made or received calls.” A cell phone functions “by connecting to a set of radio antennas called ‘cell sites.’” Cell sites are ordinarily attached to towers, but can also be attached to “light posts, flagpoles, church steeples, or the sides of buildings.” Smart phones, for instance, connect to towers “several times a minute whenever their signal is on,” and every time one “connects to a cell site” it creates a “time-stamped record known as cell-site location information (CSLI).” These cell-site records are then collected and stored by the wireless carrier for various business purposes. In Carpenter, Roberts observed that “the retrospective quality of the [cell site location information at issue] gives police access to a category of information otherwise unknowable” and “because location information is continually logged for all of the 400 million [cellular] devices in the United States . . . this newfound tracking capacity runs against everyone.”
Although Carpenter and Tuggle analyze technology in different uses and contexts, both refer to the ubiquitous nature of the technology at issue in reaching opposite results. Thus, reconciling “general public use” is not easy in the context of a Fourth Amendment search. Reversing the focus of the inquiry when determining whether a Fourth Amendment search occurred could help resolve the dilemma. Given that advanced technology is now pervasive in American society, it may make sense to ask whether status as a law enforcement official is necessary to acquire the particular technology used, rather than asking whether the technology is in general public use. Recalibrating this question may help strike an appropriate balance between public safety and personal privacy in this digital age. Otherwise, our privacy rights may erode inch by inch until we find ourselves in George Orwell’s Nineteen Eighty-Four with posters everywhere reminding us: “BIG BROTHER IS WATCHING YOU.”
*Bradley Rosen is a second-year day student at the University of Baltimore School of Law, where he is a Staff Editor for Law Review and a member of the Royal Graham Shannonhouse III Honor Society. Bradley also serves as a law scholar for Professor Hubbard’s Civil Procedure I class and Professor Lyke’s Property class. In the summer of 2021, Bradley interned for Chief Judge Beryl Howell at the United States District Court for the District of Columbia. This summer, Bradley is interning with the Public Safety and Homeland Security Bureau at the FCC, where he will be working on national security and cybersecurity matters within the Office of the Bureau Chief.
 U.S. Const. amend. IV.
 Carpenter v. United States, 138 S. Ct. 2206, 2213 (2018) (quoting Camara v. Mun. Ct. of City & Cnty. of S.F., 387 U.S. 523, 528 (1967)).
 Id. (quoting United States v. Jones, 565 U.S. 400, 405, 406 n.3 (2012)).
 Id. (quoting Soldal v. Cook Cnty., 506 U.S. 56, 64 (1992)).
 Katz v. United States, 389 U.S. 347, 351 (1967).
 Carpenter, 138 S. Ct.at 2213–14 (citing Katz, 389 U.S. at 351).
 Jones, 565 U.S. at 406 (quoting Katz, 389 U.S. at 360).
 Carpenter, 138 S. Ct. at 2213 (quoting Smith v. Maryland, 442 U.S. 735, 740 (1979)).
 See id. at 2214.
 Id. (quoting Kyllo v. United States, 533 U.S. 27, 34 (2001)).
 Kyllo, 533 U.S. at 35.
 Id. at 34 (quoting Silverman v. United States, 365 U.S. 505, 512 (1961)).
 Id. at 40 (emphasis added).
 See id. at 47 (Stevens, J., dissenting) (“[T]he contours of [the Court’s] new rule are uncertain because its protection apparently dissipates as soon as the relevant technology is ‘in general public use’ . . . [y]et how much use is general public use is not even hinted at by the Court’s opinion[.]” (internal citations omitted)).
 See In re Search of Info. Stored at Premises Controlled by Google, No. 20-297, 2020 U.S. Dist. LEXIS 165185, at *13 n.7 (N.D. Ill. July 8, 2020) (declining “to resolve whether Kyllo applies to geofencing technology.”); United States v. Arumugam, No. 19-41, 2020 U.S. Dist. LEXIS 41563, at *7–10 (W.D. Wash. Mar. 10, 2020) (finding defendant lacked a reasonable expectation of privacy using public peer-to-peer software, precluding the question as to whether the government’s alleged modifications to the software constituted technology not in general public use). But see Laura Hecht-Felella, The Fourth Amendment in the Digital Age: How Carpenter Can Shape Privacy Protections for New Technologies 6–7, Brennan Ctr. for Just. (Mar. 18, 2021), https://www.brennancenter.org/sites/default/files/2021-03/Fourth-Amendment-Digital-Age-Carpenter.pdf (describing that, “[a]s technology has transformed our society,” questions like “whether a technology is in general public use . . . have become increasingly tenuous measures of whether an individual has a reasonable expectation of privacy[,]” and that the Supreme Court addressed Kyllo’scriticisms“squarely—though not exhaustively—in Carpenter.”); Carpenter v. United States, 138 S. Ct. 2206, 2220 (2018) (“While the records in this case reflect the state of technology at the start of the decade, the accuracy of [cell site location information] is rapidly approaching GPS-level precision . . . [W]ith new technology . . . wireless carriers already have the capability to pinpoint a phone’s location within 50 meters.”). The Court concludes its “search” analysis by clarifying its “decision  is a narrow one” that does “[not] call into question conventional surveillance techniques and tools, such as security cameras.” Id. at 2221.
 Carpenter, 138 S. Ct. at 2220 (quoting Nw. Airlines, Inc. v. Minnesota, 322 U.S. 292, 300 (1944)).
 United States v. Tuggle, 4 F.4th 505, 516 (7th Cir. 2021) (quoting Kyllo v. United States, 533 U.S. 27, 40 (2001)).
 Id. at 511.
 See id.
 Id. at 516 (quoting Kyllo, 533 U.S. at 40).
 Id. (citing Carpenter v. United States, 138 S. Ct. 2206, 2220 (2018)).
 Id. (quoting Dow Chem. Co. v. United States, 476 U.S. 227, 239 (1986)).
 See, e.g., United States v. Spencer, No. 17-259, 2018 WL 1964588 (N.D. Cal. Apr. 26, 2018). In United States v. Spencer, the defendant used encryption software on an entire hard drive to conceal its contents which included child sexual exploitation imagery. Id. at *1 (finding the magistrate judge correctly applied the foregone conclusion to Spencer’s case which allowed the government to compel his hard drive’s decryption).
 Carpenter, 138 S. Ct. at 2214 (quoting Kyllo v. United States, 533 U.S. 27, 35 (2001)).
 Carpenter, 138 S. Ct. 2206.
 Id. at 2214.
 Id. at 2211.
 See id.
 Id. at 2212. Some “business purposes” include “finding weak spots in their network and applying ‘roaming’ charges when another carrier routes data through their cell sites.” Id.
 Id. at 2218 (“With access to CSLI, the Government can now travel back in time to retrace a person’s whereabouts, subject only to the retention policies of the wireless carriers, which currently maintain records for up to five years.”); Id. (“Whoever the suspect turns out to be, he has effectively been tailed every moment of every day for five years, and the police may . . . call upon the results of that surveillance without regard to the constraints of the Fourth Amendment.”).
 Compare Carpenter, 138 S. Ct. at 2217–19 (finding that the volume of information obtained from cellular location data combined with the ubiquity of cell phones made the search “unreasonable”), with Tuggle, 4 F.4th at 516–17 (finding that a search was reasonable in part because cameras are in “general public use”).
 See Carpenter, 138 S. Ct. at 2220 (“[C]arrying [a cell phone] is indispensable to participation in modern society.”).
 George Orwell, Nineteen Eighty-Four 3 (1949).