Siri — the iPhone 4S's personal-assistant feature that lets you use your voice to send messages, make calls, set reminders, and ask filthy questions — has come under fire from the American Civil Liberties Union for being a shady lady. Why? Because, it seems, she's sending Apple your precious personal data "for a variety of purposes."

In a terse press release sent out Monday, Nicole Ozer of ACLU of Northern California says:

It came as a surprise to some folks at a recent SXSW talk that Apple's Siri 'personal assistant' isn’t just working for us, it’s working full-time for Apple too by sending lots of our personal voice and user info to Apple to stockpile in its databases Take a peek at Siri's privacy policy (which, by the way, is pretty difficult to find) and you’ll realize what’s happening behind the scenes.

What info of yours is being collected and how is it being used? When you use Siri, it’s sending your “Voice Input Data” and “User Data” to Apple to be used for a variety of purposes.

Voice Input Data is all the types of data associated with your verbal commands and may also include audio recordings, transcripts of what you said, and related diagnostic data. Apple says this Voice Input Data is being used to process your request and to help Siri better recognize your commands, but it's additionally being used “generally to improve the overall accuracy and performance of Siri and other Apple products and services.”

According to the ACLU, Siri also fishes for your "User Data," which can include the names of your address book contacts, their nicknames, and their relationship with you; your first name and nickname; labels you assign to your email accounts; and names of songs and playlists in your collection.

If this concerns you, you can shut Siri down by going to Settings> General > Siri. Simply slide the Siri option to "off." Read more about privacy and Siri at ACLU.