I have lots of lock icons -- how can I get rid of them?
The icon is for Keychain Access. You can enable and disable the icon (usually there's only one) from the Keychain Access app's preferences. Try toggling this checkbox and seeing what happens.

Multiple icons is sometimes a rare glitch where other menu bar items appear with the wrong icon, taking on the appearance of a different item. This can usually be fixed by killing SystemUIServer (killall -HUP SystemUIServer).

If it really is multiple menu bar items, you can remove them by ⌘-dragging them away from the menu bar.