Here’s a fascinating article from Phys.org on how the US DOJ is getting cellular location data from cell carriers (neatly bypassing the 4th amendment protections) and how technology has increased the reach of the government into our daily lives.
Is using cell-phone data for tracking purposes a violation of privacy? Does it violate any constitutional requirements?
The short answer is: We don’t know. The Supreme Court hasn’t decided yet, though police are clearly doing it all the time. The basic test of what violates the Fourth Amendment is whether the government action is “unreasonable” search and seizure. The Supreme Court has just decided, in the United States v. Jones case, that it’s unreasonable for police to attach a GPS tracker to someone’s car in order to remotely monitor that car’s movements full time for a month, without first getting a warrant.
…
The biggest threats to our privacy nowadays are probably those we create for ourselves, by giving out information to make our lives easier. Through the use of credit cards, email and mobile devices, we allow many private entities to collect all kinds of information about us, and, where it isn’t protected by some statute, those entities can sell that information to anyone willing to pay for it. The Constitution can’t protect us very well against giving our information away.
What obligation do service providers have to give tracking data to law-enforcement agencies, particularly when no warrant has been obtained?
[the cellphone carrier] may be willing to sell that information, if the price is right, and if it thinks that its customers won’t care, or won’t notice.
…
How has the pervasiveness of digital content and growing digital footprints influenced law-enforcement practices? In general, does it complicate or aid criminal investigations?
in addition to GPS tracking (which can be performed by police with a warrant), the government is likely to collect all the electronic information it can get in order to help prove its case: cell-phone data, hard drives, emails, credit card, bank transactions, etc. Digital-evidence collection has vastly increased the amount of data that must be processed, and it requires entirely new kinds of expertise. The courts are still sorting out just how far police can go in looking through someone’s hard drive if they have probable cause to believe that they’ll find incriminating information.