Document ID: ./input/supremecourt_opinions/opinions/17pdf/16-402_h315.pdf
Page Number: 66

16 

CARPENTER v. UNITED STATES 

THOMAS, J., dissenting 

regulated  by  a  robust  body  of  common-law  rules.  See 
generally  W.  Cuddihy,  The  Fourth  Amendment:  Origins
and  Original  Meaning  602–1791  (2009);  e.g.,  Wilson  v. 
Arkansas,  514  U. S.  927,  931–936  (1995)  (discussing  the 
common-law  knock-and-announce  rule).    The  search-and­
seizure  practices  that  the  Founders  feared  most—such  as
general warrants—were already illegal under the common
law, and jurists such as Lord Coke described violations of
the common law as “against reason.”  See Donahue 1270– 
1271,  and  n. 513.    Locke,  Blackstone,  Adams,  and  other 
influential  figures  shortened  the  phrase  “against  reason”
to  “unreasonable.”  See  id.,  at  1270–1275.    Thus,  by  pro­
hibiting  “unreasonable”  searches  and  seizures  in  the
Fourth Amendment, the Founders ensured that the newly 
created  Congress  could  not  use  legislation  to  abolish  the 
established common-law rules of search and seizure.  See 
T. Cooley, Constitutional Limitations *303 (2d ed. 1871); 3
J. Story, Commentaries on the Constitution of the United 
States §1895, p. 748 (1833).

Although the Court today maintains that its decision is 
based  on  “Founding-era  understandings,”  ante,  at  6,  the 
Founders  would  be  puzzled  by  the  Court’s  conclusion  as
well  as  its  reasoning.  The  Court  holds  that  the  Govern­
ment  unreasonably  searched  Carpenter  by  subpoenaing
the  cell-site  records  of  Sprint  and  MetroPCS  without  a 
warrant.    But  the  Founders  would  not  recognize  the 
Court’s “warrant requirement.”  Ante, at 21.  The common 
law  required  warrants  for  some  types  of  searches  and 
seizures,  but  not  for  many  others.    The  relevant  rule  de­
pended on context.  See Acevedo, supra, at 583–584 (opin­
ion  of  Scalia,  J.);  Amar,  Fourth  Amendment  First  Princi­
ples,  107  Harv.  L.  Rev.  757,  763–770  (1994); Davies  738–
739.  In  cases  like  this  one,  a  subpoena  for  third-party 
documents was not a “search” to begin with, and the com­
mon  law  did  not  limit  the  government’s  authority  to  sub­
poena third parties.  See post, at 2–12 (ALITO, J., dissent­