OPLIN list firestorm

There is a bit of a firestorm going on the OPLIN list-serv discussing one library's decision to disallow patrons to check out books if they have > $0 balance on their accounts.

Many people, including myself, find this less than desirable. While it is not necessarily a punishment, the plan leaves a very sour taste in my mouth.
In these tough economic times, we need to innovate to find new ways that we can raise funds. Yes, fines are a revenue source. But we should *never* rely on that and hold our books hostage. Fines are merely to deter the patron from keeping the books.
It would be fantastic if we were able to move to a model of "If you want to keep it, we'll bill you for it, no questions asked." That way, we can replace that book immediately. Should a book be irreplacable, we should scan those. The patron is still billed for keeping the book but the digital copy will be also available.
Irreplacable is typically out-of-print. Out-of-print does not necessarily mean out of copyright so that would be something to consider.

By no means have I figured out the perfect solution to the library fines dilemma. However, zero balance for checkout is not an option.