Have an iPhone and/or iPad? Keep your contacts and calendar synchronized to a computer locally, so that the information is only shared among devices you control and is never sent over the Internet? Concerned about Apple harvesting data (regardless of what the legally engineered privacy statement says) on who you know, who you're related to, who you work with, data on exactly where you go every day, when you arrive there and leave, what you're doing? Concerned about other companies getting some of this data? Online hackers? Don't want the National Security Agency to get it and share it with other government agencies, the kind of data that Edward Snowden revealed the NSA specifically goes after, that they claim you don't have any 4th Amendment protection to keep private?
Too bad for you. With the new computer operating system, "Mavericks," Apple now demands that you hand over all that personal information to them, that you run it through iCloud.
OS X MAVERICKS FORCES IOS CALENDAR, CONTACT SYNCING INTO ICLOUD
By Molly Wood, Oct. 27, 2013
The relationship between your computer and your iDevices is about to get a lot less personal.
Or, you could not synchronize it. You could, you know, lose the functionality that a Palm device from a over decade ago had. Render dumb and pointless the electronics that you've spent a fair bit of money buying and a significant chunk of time configuring.
In now demanding this from you, Apple was too cowardly to even announce the demand. They let you fumble around thinking that there's some kind of bug or glitch or that you messed something up, until maybe you figured out what's going on. "It just works," they say, so long as you just do what they tell you to do and expose your private information to exploitation. Or, in this case, do what they didn't tell you.
There may be work-arounds, for those with nearly professional-level information technology skills. Perhaps there will soon be a third-party patch in the form of an app for that too.
But as it stands, this is Apple's worst attack on your privacy (that is, other than the small matter of their direct and indirect collusion with the NSA!) since they let any app steal your address book and calendar without your permission, something that they didn't care about until there was public anger over it among the user community.
UPDATE March 30, 2013: There is a way to synchronize iPhone calendar and contacts locally, without resorting to command-line system changes.
Security SpreadUPDATE May 19, 2013: Well, lookee there. Apple has restored local sync of contacts and calendars in its latest software updates.
Setting up your own OS X Sync Server
Apple releases OS X 10.9.3 with improved 4K support, restored USB sync
iCloud-circumventing local sync makes a return, also requires iTunes update.
By Andrew Cunningham, May 15 2014
In The Loop/The Apple Ecosystem, Ars Technica