The other day I found out that my local library has no limit on how many items a person can check out at once.
I asked the librarian, "What's to stop someone from driving up with a UHaul and filling it up?"
And she replied, with a grin, "Ambition"
I work at a library and until Monday we didn't have a limit either. Last month someone got "ambition" and checked out 151 of the community's books. They're overdue now and we don't expect them back. We now have a limit of 50 (which still seems like a lot).