Frustrated librarians want the worst offenders to face criminal charges and up to 90 days behind bars.
"We want to go after some of the people who owe us a lot of money," said Frederick J. Paffhausen, the library's system director. "We want to set an example."
Paffhausen, who took over as director in October, is asking the Bay County Library Board for permission to seek arrest warrants for offenders who ignore repeated notices. The board plans to consider the crackdown next month.
One patron from Bad Axe owes $1,190 for 73 items -- mainly science-fiction books -- hoarded for more than a year, Paffhausen said.
Patrons keep an average of $25,000 in overdue materials out of the library system each year, officials said.
That costs taxpayers money, because the library often must buy copies to replace unreturned materials, leaving less for new books, CDs and DVDs, Paffhausen said.
Currently, the library cuts off an offending patron's privileges and sends overdue notices. Daily fines of 5 to 10 cents per item are assessed. If the material is worth $75 or more, the patron receives a form letter from the prosecutor's office warning that it's a crime to keep library items.