The American Civil Liberties Union stumbled upon a document submitted to the court during a drug investigation headed up by Immigration and Customs Enforcement. The document lists the data that ICE officials were able to pull off an iPhone, and it's striking how much information that one small device can hold.
According to the report, ICE snagged the iPhone from a suspect's bedroom during a drug bust and subjected the phone to one data extraction session. During that sweep, officials were able to obtain the following personal information:
- call activity for 104 calls
- phone book directory information for 18 contacts
- stored voicemails and text messages
- photos and videos
- details from 37 installed apps
- eight different passwords
- 659 geolocation points, including 227 cell towers and 403 WiFi networks with which the cell phone had previously connected.
As pointed out by the ACLU, analysis of this data provides information on every nook and cranny of the suspect's life and is a wealth of information that was not available to police before smartphones became prevalent.
Warrants were obtained in this particular investigation, but the ACLU notes that warrants aren't always needed to search a cell phone. And with portable cell phone forensic machines more readily available to law enforcement, the contents of your phone are only a keypress away.
In the end the best way to keep your phone away from prying eyes (government, thieves or curious friends) is to use a strong passcode and disk encryption if that option is available on your phone. You can read more about cell phone searches and this case in the ACLU article.