The law normally advances by small and cautious steps—by the gradual extension of established precedents and rules to novel problems and fact patterns. Little wonder, then, that tricky questions of law often amount to conflicts between competing metaphors. Is a hard drive like a closed briefcase whose contents are all fair game for police once the “container” is legitimately opened? Or is it more like a warehouse containing hundreds or thousands of individual closed containers? If the latter, what are the “containers”? Directories? Individual files?
A similar metaphor war figures in the FBI’s effort to expand its authority to acquire information from Internet Service Providers using National Security Letters, which are issued by agents without judicial oversight, and typically forbid providers from disclosing anything about the demand for records. The Bureau had long assumed that the NSL statutes gave them broad authority to get “electronic communications transaction records”—information about your online communications, though not the contents of the communications themselves—as long as they certified that those records would be “relevant” to a national security investigation, a far lower standard than the Fourth Amendment’s “probable cause.” But in a 2008 opinion, the Bush administration’s Office of Legal Counsel rejected this interpretation, finding that NSLs could only be used to obtain the particular types of records specified in the statute, including “toll billing records.” For Internet accounts, this meant the FBI could only get “information parallel to… toll billing records for ordinary telephone service.”
The obvious question is what, exactly, constitutes information “parallel to” a toll billing record in the online context. The FBI would prefer to resolve the ambiguity by simply amending the law to give them blanket authority to acquire transaction records. In particular, according to The Washington Post, government lawyers think they can obtain “the addresses to which an Internet user sends e‑mail; the times and dates e‑mail was sent and received; and possibly a user’s browser history.” On its face, this sounds like a reasonable reading. An important 1979 Supreme Court case, Smith v. Maryland, held that the information contained in telephone “toll billing records”—the itemized list of calls placed and received you’d find on a standard phone bill—didn’t enjoy Fourth Amendment protection, and so unlike the contents of phone conversations themselves, could be obtained by the government without a full probable cause warrant. Surely the obvious equivalent in the online context is the list of e‑mail addresses in an Internet user’s inbox and outbox? At a second glance, though, there are some problems with that metaphor, of two central kinds.