October Term 2017 · Docket 16-402

Does the Fourth Amendment require a warrant for long-term cell site location data?

The government collected 127 days of cell site data without a warrant. the side that brought the case argues this violates privacy rights. The government claims the data is merely business records.

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Carpenter v. United States
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Verified source milestones

  1. — An official oral-argument transcript was verified.
  2. — An official oral-argument transcript was verified.

The arguments, in order

This case may have been argued more than once. Each entry below uses that session's official transcript. Later arguments do not erase earlier ones.

  1. Argument 1 ·

    What happened at the argument

    Mr. Wessler argued the government collected 127 days of location data without a warrant.

    Mr. Dreeben argued cell companies function as witnesses producing their own business records.

    Justice Alito questioned why location data is more sensitive than bank records showing purchases.

    Justice Kennedy countered that physical location is publicly visible, unlike private bank records.

    Read the official transcript for this argument · Official argument details

    Sources used for this argument breakdown

A citizen's guide to the whole case

What this case is about

This case tests whether the Fourth Amendment protects cell site location information. The government collected 127 days of data without a warrant. the side that brought the case argues this reveals private movements. The government argues the data is public business records.

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How the case got here

The Supreme Court heard oral argument in this case on November 29, 2017.

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What each side wants

the side that brought the case wants the Court to require a warrant for this data.

The government wants the Court to allow warrantless collection of this data.

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What each side says

the side that brought the case argues long-term location data reveals private movements and associations.

The government argues cell companies are merely witnesses producing business records.

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What the justices asked

Justice Alito asked why location data is more sensitive than bank records.

Justice Kennedy argued location data is less private than bank records because people can be seen in public.

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Why it matters

This dispute defines the scope of digital privacy protections. It determines whether the government needs judicial approval to track individuals over time. The outcome shapes how law enforcement accesses modern communication records.

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What happens next

This article currently covers the argument record. Use the official docket link for later case activity.

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Official Court provenance

Official docket and case history · Official Supreme Court oral-argument detail page

Title and summary sources

Revision history

  1. Revision 1 · Official Transcript ·

    Correction: Rewritten to the concise citizen-facing editorial standard.

  2. Revision 2 · Official Transcript ·

    Correction: Migrated to the dated official Court activity contract without model use.

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