Can law enforcement obtain a search warrant to dig through a vast trove of e-mails, instant messages and chat logs because they have reasonable suspicion that the owners of those accounts robbed computer equipment from a private company?
No, according to a ruling by a federal judge in Kansas earlier this week.
The case is significant in that it limits what constitutes unreasonable search and seizure, as protected by the Fourth Amendment, in the age of big data. The magistrate judge, David J. Waxse, denied the government’s search warrant requests on the grounds that it has to be particular and “reasonable in nature of breadth.”
Orin Kerr, a law professor at George Washington University and an expert on surveillance law, interpreted it this way on Twitter: “You can’t look through the kitchen sink to get the evidence, as you do with physical searches.”
Prosecutors sought search warrants to extract information from Verizon, an Internet service provider, GoDaddy, a Web site hosting company, along with Web communications companies Google, Skype and Yahoo on account holders suspected of having stolen $5,000 in computer equipment from Sprint.
The government believed that the suspects used e-mail and instant-message accounts to “facilitate the purchase, receipt and transportation of the equipment” from Kansas to New Jersey. The government sought “contents of all emails, instant messages and chat logs/sessions — and other...