Representing a potential privacy snare for some users, Mac OS X Yosemite uploads documents opened in TextEdit, Preview, and Keynote to iCloud servers by default, even if the files are later closed without ever having been saved.
The behavior, as noted in an article from Slate, is documented in a Knowledge Base article from December. But it nonetheless came as a surprise to researcher Jeffrey Paul, who said he was alarmed to recently discover a cache of in-progress files he intended to serve as "temporary Post-It notes" that had been silently uploaded to his iCloud account even though he never intended or wished them to be.
"Apple has taken local files on my computer not stored in iCloud and silently and without my permission uploaded them to their servers," Paul wrote in a recent blog post.