This is fantastic news.
Justice Kennedy’s dissent, however, shows the dangerous thinking on the other side:
“‘Cell-site records,’ he wrote, ‘are uniquely suited to help the government develop probable cause to apprehend some of the nation’s most dangerous criminals: serial killers, rapists, arsonists, robbers, and so forth.’”
Indeed. That same data is intensely personal, however, and there’s nothing stopping law enforcement from obtaining it, after getting a judge to agree that there’s a reasonable foundation to inspect it.