Why did people argue that accessing a cellphone without a warrant violated the Fourth Amendment?

Choices:
A. not enough information
B. it would be a case of unreasonable search and seizure
C. it would be a case of lacking freedom of speech
D. it would be a case of hacking
it would be a case of unreasonable search and seizure
The U.S. Supreme Court signaled Wednesday it may be open to new limits on the government's ability to track someone's movements by accessing data on that person's cellphone.

A case before the high court could result in a landmark decision in the ongoing debate over civil liberties protections in an era of rapid technological change.

At issue is whether law enforcement will be able to access cellphone data that can reveal a person's whereabouts without having to first obtain a court-issued search warrant.

The case stems from the conviction of Timothy Carpenter for a series of robberies back in 2010 and 2011. Prosecutors were able to obtain cellphone records that indicated his location over a period of months, information that proved crucial to his conviction.
On Wednesday, lawyers for the American Civil Liberties Union argued that law enforcement should be required to obtain a court-ordered search warrant before obtaining such information.

They also argued that allowing law enforcement to access the cellphone data without a warrant would violate the prohibition on unreasonable search and seizures contained in the Fourth Amendment to the U.S. Constitution.

"It is impossible to go about our daily lives without leaving a trail of digital breadcrumbs that reveal where we have been over time, what we have done, who we spent time with," said ACLU attorney Nathan Freed Wessler, who spoke to reporters outside the Supreme Court following oral arguments. "It is time for the court, we think, to update Fourth Amendment doctrine to provide reasonable protections today."

Some of the justices also raised concerns about privacy in the digital age.

"Most Americans, I think, still want to avoid Big Brother," Justice Sonia Sotomayor, who often sides with the liberal wing of the court, said.

Chief Justice John Roberts, who often sides with conservatives on the court, said the central question was whether the cellphone information should be accessible to the government "without a warrant."