This card was used in a phone without a large amount of write stress (which does shorten the life of the card - it was not written to over and over in the phone).The card is now totally unwriteable - on a Mac, a Linux machine, or the phone - writes all "seem" to succeed but even low-level reformats don't actually *do* anything - the exact same files are there after every change, untouchable and frozen forever.10 months of use out of a memory card and then a really weird failure like this (neither the Mac, Linux machine, or phone reports any error) is not acceptable quality from SanDisk.