Joseph Pierpoint discovered a folder in his Trash labeled “Lost & Found.” When he opened it, he found it contained over 50,000 files. Worse, “Any attempts to send these files to the Trash are thwarted by interruptions that state that this kind of solution is infeasible for one reason or another.”
The Lost & Found folder relates to a low-level Unix filesystem-recovery utility. When
fsck (filesystem check) runs, it looks not just at files that appear properly referenced in a filesystem’s directory, but also at anything it finds that looks like a file but isn’t appropriately noted in that record structure. In Unix, it stores these recovered bits in a folder named
lost+found. macOS exposes recovered files in Lost & Found, and drops it in the Trash because these items typically aren’t useful, but it doesn’t delete them in case a user wants to examine what was recovered.