One of these days this decision will be seen as our generations Dred
Scott. Everyone will wonder, "What *were* they THINKING?"

Captain Compassion wrote:

No Expectation of Privacy.

"Petitioner in all probability entertained no actual expectation of
privacy in the phone numbers he dialed, and even if he did, his
expectation was not "legitimate." First, it is doubtful that telephone
users in general have any expectation of privacy regarding the numbers
they dial, since they typically know that they must convey phone
numbers to the telephone company and that the company has facilities
for recording this information and does in fact record it for various
legitimate business purposes. And petitioner did not demonstrate an
expectation of privacy merely by using his home phone rather than some
other phone, since his conduct, although perhaps calculated to keep
the contents of his conversation private, was not calculated to
preserve the privacy of the number he dialed. Second, even if
petitioner did harbor some subjective expectation of privacy, this
expectation was not one that society is prepared to recognize as
"reasonable." When petitioner voluntarily conveyed numerical
information to the phone company and "exposed" that information to its
equipment in the normal course of business, he assumed the risk that
the company would reveal the information [442 U.S. 735, 736] to the
police, cf. United States v. Miller, 425 U.S. 435 . Pp. 741-746.

SMITH v. MARYLAND, 442 U.S. 735 (1979)
http://caselaw.lp.findlaw.com/scripts/getcase.pl?navby=case&court=us&vol=442&page=735