What information does Siri collect and save?
Apple revealed that Siri stores a user's data for up to two years. Apple spokeswoman Trudy Muller told Wired.com that all queries are transferred to Apple’s data farm, where a random number is generated to represent the user. The user number is “disassociated" from the voice file after six months, but the voice data is kept for up to 18 more months for "testing and product improvement purposes".
“Apple may keep anonymized Siri data for up to two years,” Muller said. “If a user turns Siri off, both identifiers are deleted immediately along with any associated data.”