Computer Used to Obtain Unauthorized Access to a Computer ("Hacking")
Your affiant knows that when an individual uses a computer to obtain unauthorized access to a victim computer over the Internet, the individual's computer will generally serve both as an instrumentality for committing the crime, and also as a storage device for evidence of the crime. The computer is an instrumentality of the crime because it is "used as a means of committing [the] criminal offense" according to Rule 41(b )(3). In particular, the individual's computer is the primary means for accessing the Internet, communicating with the victim computer, and ultimately obtaining the unauthorized access that is prohibited by 18 U.S.C. § 1030. The computer is also likely to be a storage device for evidence of crime because computer hackers generally maintain records and evidence relating to their crimes on their computers. Those records and evidence may include files that recorded the unauthorized access, stolen passwords and other information downloaded from the victim computer, the individual's notes as to how the access was achieved, records of Internet chat discussions about the crime, and other records that indicate the scope of the individual's unauthorized access.
Computers Used to Produce Child Pornography
It is common for child pornographers to use personal computers to produce both still and moving images. For example, a computer can be connected to avideo camera, VCR, or DVD-player, using a device called a video capture board: the device turns the video output into a form that is usable by computer programs. Alternatively, the pornographer can use a digital camera to take photographs or videos and load them directly onto the computer. The output of the camera can be stored, transferred or printed out directly from the computer. The producers of child pornography can also use a device known as a scanner to transfer photographs into a computer-readable format. All of these devices, as well as the computer, constitute instrumentalities of the crime.
2. When the Computer Is Merely a Storage Device for Contraband, Evidence, And/or an Instrumentality or Fruit of Crime
When the computer is merely a storage device for electronic evidence, the affidavit should explain this clearly. The affidavit should explain why there is probable cause to believe that evidence of a crime may be found in the location to be searched. This does not require the affidavit to establish probable cause that the evidence may be stored specifically within a computer. However, the affidavit should explain why the agents believe that the information may in fact be stored as an electronic file stored in a computer.
Your affiant knows that child pornographers generally prefer to store images of child pornography in electronic form as computer files. The computer's ability to store images in digital form makes a computer an ideal repository for pornography. A small portable disk can contain hundreds or thousands of images of child pornography, and a computer hard drive can contain tens of thousands of such images at very high resolution. The images can be easily sent to or received from other computer users over the Internet. Further, both individual files of child pornography and the disks that contain the files can be mislabeled or hidden to evade detection.
Illegal Business Operations
Based on actual inspection of [spreadsheets, financial records, invoices], your affiant is aware that computer equipment was used to generate, store, and print documents used in [suspect's] [tax evasion, money laundering, drug trafficking, etc.] scheme. There is reason to believe that the computer system currently located on [suspect's] premises is the same system used to produce and store the [spreadsheets, financial records, invoices], and that both the [spreadsheets, financial records, invoices] and other records relating to [suspect's] criminal enterprise will be stored on [suspect's computer].
D. The Search Strategy
The affidavit should also contain a careful explanation of the agents' search strategy, as well as a discussion of any practical or legal concerns that govern how the search will be executed. Such an explanation is particularly important when practical considerations may require that agents seize computer hardware and search it off-site when that hardware is only a storage device for evidence of crime. Similarly, searches for computer evidence in sensitive environments (such as functioning businesses) may require that the agents adopt an incremental approach designed to minimize the intrusiveness of the search. The affidavit should explain the agents' approach in sufficient detail that the explanation provides a useful guide for the search team and any reviewing court. It is a good practice to include a copy of the search strategy as an attachment to the warrant, especially when the affidavit is placed under seal. Here is sample language that can apply recurring situations:
1. Sample Language to Justify Seizing Hardware and Conducting a Subsequent Off-site Search
Based upon your affiant's knowledge, training and experience, your affiant knows that searching and seizing information from computers often requires agents to seize most or all electronic storage devices (along with related peripherals) to be searched later by a qualified computer expert in a laboratory or other controlled environment. This is true because of the following:
(1) The volume of evidence. Computer storage devices (like hard disks, diskettes, tapes, laser disks) can store the equivalent of millions of information. Additionally, a suspect may try to conceal criminal evidence; he or she might store it in random order with deceptive file names. This may require searching authorities to examine all the stored data to determine which particular files are evidence or instrumentalities of crime. This sorting process can take weeks or months, depending on the volume of data stored, and it would be impractical and invasive to attempt this kind of data search on-site.
(2) Technical Requirements. Searching computer systems for criminal evidence is a highly technical process requiring expert skill and a properly controlled environment. The vast array of computer hardware and software available requires even computer experts to specialize in some systems and applications, so it is difficult to know before a search which expert is qualified to analyze the system and its data. In any event, however, data search protocols are exacting scientific procedures designed to protect the integrity of the evidence and to recover even "hidden," erased, compressed, password-protected, or encrypted files. Because computer evidence is vulnerable to inadvertent or intentional modification or destruction (both from external sources or from destructive code imbedded in the system as a "booby trap"), a controlled environment may be necessary to complete an accurate analysis. Further, such searches often require the seizure of most or all of a computer system's input/output peripheral devices, related software, documentation, and data security devices (including passwords) so that a qualified computer expert can accurately retrieve the system's data in a laboratory or other controlled environment.
In light of these concerns, your affiant hereby requests the Court's permission to seize the computer hardware (and associated peripherals) that are believed to contain some or all of the evidence described in the warrant, and to conduct an off-site search of the hardware for the evidence described, if, upon arriving at the scene, the agents executing the search conclude that it would be impractical to search the computer hardware on-site for this evidence.
2. Sample Language to Justify an Incremental Search
Your affiant recognizes that the [Suspect] Corporation is a functioning company with approximately [number] employees, and that a seizure of the [Suspect] Corporation's computer network may have the unintended and undesired effect of limiting the company's ability to provide service to its legitimate customers who are not engaged in [the criminal activity under investigation]. In response to these concerns, the agents who execute the search will take an incremental approach to minimize the inconvenience to [Suspect Corporation]'s legitimate customers and to minimize the need to seize equipment and data. This incremental approach, which will be explained to all of the agents on the search team before the search is executed, will proceed as follows:
A. Upon arriving at the [Suspect Corporation's] headquarters on the morning of the search, the agents will attempt to identify a system administrator of the network (or other knowledgeable employee) who will be willing to assist law enforcement by identifying, copying, and printing out paper [and electronic] copies of [the computer files described in the warrant.] If the agents succeed at locating such an employee and are able to obtain copies of the [the computer files described in the warrant] in that way, the agents will not conduct any additional search or seizure of the [Suspect Corporation's] computers.
B. If the employees choose not to assist the agents and the agents cannot execute the warrant successfully without themselves examining the [Suspect Corporation's] computers, primary responsibility for the search will transfer from the case agent to a designated computer expert. The computer expert will attempt to locate [the computer files described in the warrant], and will attempt to make electronic copies of those files. This analysis will focus on particular programs, directories, and files that are most likely to contain the evidence and information of the violations under investigation. The computer expert will make every effort to review and copy only those programs, directories, files, and materials that are evidence of the offenses described herein, and provide only those items to the case agent. If the computer expert succeeds at locating [the computer files described in the warrant] in that way, the agents will not conduct any additional search or seizure of the [Suspect Corporation's] computers.
C. If the computer expert is not able to locate the files on-site, or an on-site search proves infeasible for technical reasons, the computer expert will attempt to create an electronic "image" of those parts of the computer that are likely to store [the computer files described in the warrant]. Generally speaking, imaging is the taking of a complete electronic picture of the computer's data, including all hidden sectors and deleted files. Imaging a computer permits the agents to obtain an exact copy of the computer's stored data without actually seizing the computer hardware. The computer expert or another technical expert will then conduct an off-site search for [the computer files described in the warrant] from the "mirror image" copy at a later date. If the computer expert successfully images the [Suspect Corporation's] computers, the agents will not conduct any additional search or seizure of the [Suspect Corporation's] computers.
D. If "imaging" proves impractical, or even impossible for technical reasons, then the agents will seize those components of the [Suspect Corporation's] computer system that the computer expert believes must be seized to permit the agents to locate [the computer files described in the warrant] at an off-site location. The components will be seized and taken in to the custody of the FBI. If employees of [Suspect Corporation] so request, the computer expert will, to the extent practicable, attempt to provide the employees with copies of any files [not within the scope of the warrant] that may be necessary or important to the continuing function of the [Suspect Corporation's] legitimate business. If, after inspecting the computers, the analyst determines that some or all of this equipment is no longer necessary to retrieve and preserve the evidence, the government will return it within a reasonable time.
3. Sample Language to Justify the Use of Comprehensive Data Analysis Techniques
Searching [the suspect's] computer system for the evidence described in [Attachment A] may require a range of data analysis techniques. In some cases, it is possible for agents to conduct carefully targeted searches that can locate evidence without requiring a time-consuming manual search through unrelated materials that may be commingled with criminal evidence. For example, agents may be able to execute a "keyword" search that searches through the files stored in a computer for special words that are likely to appear only in the materials covered by a warrant. Similarly, agents may be able to locate the materials covered in the warrant by looking for particular directory or file names. In other cases, however, such techniques may not yield the evidence described in the warrant. Criminals can mislabel or hide files and directories; encode communications to avoid using key words; attempt to delete files to evade detection; or take other steps designed to frustrate law enforcement searches for information. These steps may require agents to conduct more extensive searches, such as scanning areas of the disk not allocated to listed files, or opening every file and scanning its contents briefly to determine whether it falls within the scope of the warrant. In light of these difficulties, your affiant requests permission to use whatever data analysis techniques appear necessary to locate and retrieve the evidence described in [Attachment A].
E. Special Considerations
The affidavit should also contain discussions of any special legal considerations that may factor into the search or how it will be conducted. These considerations are discussed at length in Chapter 2. Agents can use this checklist to determine whether a particular computer-related search raises such issues:
1. Is the search likely to result in the seizure of any drafts of publications (such as books, newsletters, Web site postings, etc.) that are unrelated to the search and are stored on the target computer? If so, the search may implicate the Privacy Protection Act, 42 U.S.C. § 2000aa.
2. Is the target of the search an ISP, or will the search result in the seizure of a mail server? If so, the search may implicate the Electronic Communications Privacy Act, 18 U.S.C. §§ 2701-12.
3. Does the target store electronic files or e-mail on a server maintained in a remote location? If so, the agents may need to obtain more than one warrant.
4. Will the search result in the seizure of privileged files, such as attorney-client communications? If so, special precautions may be in order.
5. Are the agents requesting authority to execute a "sneak-and-peek" search? If so, the proposed search must satisfy the standard defined in 18 U.S.C. § 3103a(b).
6. Are the agents requesting authority to dispense with the "knock and announce" rule?