When I see the badges list, I'm unsure which ones are being capable of being won more than once. Could we highlight these badges in some way?
EDIT: I reviewed the entire list today, and if you click on each badge, you'll see the text "This badge can be awarded multiple times." (as Jeff points out) for those badges that can be won more than once. The key is though that you have to click through to see it. I've edited TheTXI's answer to show what is now current.
This feature request is for the badges page to show which ones can be won multiple times, so you don't have to go to every badge page to figure it out.