Representative Ann Williams sponsored the legislation. When it was debated back in May, the Chicago Democrat said it was meant to ensure peoples' privacy.
"This bill in no way limits the use for important law enforcement needs. What it does is ensure that the privacy protections afforded to us under the Constitution -- under the First and the Fourth Amendment -- are intact."
The law has several exceptions in which police wouldn't need a warrant including searches for missing people, when someone is in imminent danger, or when the federal government identifies a credible terrorist threat.