Document ID: ./input/supremecourt_opinions/opinions/17pdf/16-402_h315.pdf
Page Number: 9

Cite as:  585 U. S. ____ (2018) 

5 

Opinion of the Court 

mage  through  homes  in  an  unrestrained  search  for  evi-
dence  of  criminal  activity.”  Riley  v.  California,  573  U. S. 
___,  ___  (2014)  (slip  op.,  at  27).    In  fact,  as  John  Adams 
recalled, the patriot James Otis’s 1761 speech condemning 
writs  of  assistance  was  “the  first  act  of  opposition  to  the 
arbitrary  claims  of  Great  Britain”  and  helped  spark  the
Revolution itself.  Id., at ___–___ (slip op., at 27–28) (quot-
ing 10 Works of John Adams 248 (C. Adams ed. 1856)). 

For  much  of  our  history,  Fourth  Amendment  search
doctrine was “tied to common-law trespass” and focused on 
whether  the  Government  “obtains  information  by  physi-
cally  intruding  on  a  constitutionally  protected  area.” 
United States v. Jones, 565 U. S. 400, 405, 406, n. 3 (2012).
More  recently,  the  Court  has  recognized  that  “property
rights  are  not  the  sole  measure  of  Fourth  Amendment
violations.”  Soldal  v.  Cook  County,  506  U. S.  56,  64 
(1992).  In Katz v. United States, 389 U. S. 347, 351 (1967),
we  established  that  “the  Fourth  Amendment  protects
people,  not  places,”  and  expanded  our  conception  of  the 
Amendment  to  protect  certain  expectations  of  privacy  as 
well.  When an individual “seeks to preserve something as 
private,” and his expectation of privacy is “one that society 
is prepared to recognize as reasonable,” we have held that 
official  intrusion  into  that  private  sphere  generally  quali-
fies  as  a  search  and  requires  a  warrant  supported  by
probable cause.  Smith, 442 U. S., at 740 (internal quota-
tion marks and alterations omitted).

Although  no  single  rubric  definitively  resolves  which
expectations  of  privacy  are  entitled  to  protection,1  the 

—————— 

1 JUSTICE KENNEDY believes that there is such a rubric—the “proper-
ty-based  concepts”  that  Katz  purported  to  move  beyond.  Post,  at  3 
(dissenting  opinion).    But  while  property  rights  are  often  informative, 
our  cases  by  no  means  suggest  that  such  an  interest  is  “fundamental” 
or  “dispositive”  in  determining  which  expectations  of  privacy  are 
legitimate.    Post,  at  8–9.  JUSTICE  THOMAS  (and  to  a  large  extent 
JUSTICE  GORSUCH)  would  have  us  abandon  Katz  and  return  to  an