I've researched this heavily and I can't for the life of me figure it out. My problem is simple: I have Lastpass. Lastpass is great! However, I also have a bunch of saved passwords in my iCloud Keychain from when I was relying on that for password management. No matter what I do, iCloud Keychain passwords autofill in my browser, requiring me to manually overwrite them using the Lastpass widget. Chrome is set to not do auto-fill but apparently Keychain trumps Chrome. This is a minor nuisance in effect, but it's unsettling that I simply cannot remove these passwords from my keychain. I launch Keychain Access, delete all Internet Passwords from the login keychain (I've tried deleting them as a group, deleting one at a time, etc.), and for a short time thereafter all is well, until at some point my passwords re-sync with the cloud and my Internet Passwords are back. You'd think that by deleting them, I would be deleting them from iCloud but, well, no, apparently not. I tried disabling iCloud Keychain. This was a total cluster*#(%. Suddenly, almost all of my OS X apps were seemingly incapable of storing login credentials. I tried deleting the login keychain, but it repopulates from iCloud. I guess, simply put: how the heck do I just flush all of my passwords from my iCloud Keychain? And why is this so bloody difficult?