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iPhone owners say the latest iOS update is resurfacing deleted nudes
(www.theverge.com)
This is a most excellent place for technology news and articles.
A single overwrite might not be enough to defeat physical forensics because shadows of the old data persist in how the new data is stored. Also when it comes to SSDs you might be waiting a long time for the data to get overwritten as the drive will wear-level its erm sectors (what are those things called with SSDs?).
They are called cells IIRC