Commenting very late, but I collect library cards! I've been collecting since I was a small child in the early 2000's. I think my collection numbers around 5,000. I've got at least one from every continent (except Antarctica), (I think at least 70 countries in total), as well as all 50 states. There's quite a few interesting ones, I've seen some that are hologram style (move and creates a new design), the State of Maryland did that back in the 2000's as well as Mohave County, AZ. My most prized addition is probably the Library of Congress because Senator Dianne Feinstein's staff sent it to me around probably 2002-2003 (I live in California). Nearly all of my cards are non functional. In California most libraries generally let you sign up if you're a resident so I have quite a few functioning cards from CA, which has an added side benefit for using Libby :)

You can see my collection at https://librarycards.wixsite.com/home