Macgasm - The terminal is a pretty powerful tool in Mac OS X. Hardcore server nuts can fly through preferences and settings tweaks without ever touching a GUI. Then there are some things you can do in the Terminal that are just straight out important. This is likely one of the latter, though it does present a bit of a privacy issue. According to OS X Daily the Launch Services quarantine keeps a list of every file you’ve ever downloaded on your Mac, as that’s what triggers the warning dialog about opening files from the Internet. Oddly enough, even if you’ve disabled this in the command line, the database is still keeping track.