The Wisconsin Library Association has a good explanation of the recent state attorney general opinion finding library surveillance tapes protected as library records under state law. Unfortunately, in my estimation, the proposed amendment seems to be written more broadly than it need be.
5) Library records may be released for administrative library purposes, including establishment or maintenance of a system to manage the library records or to assist in the transfer of library records from one records management system to another, compilation of statistical data on library use, collection of fines and penalties, and the protection of library staff, library users, and library property. Records released to third parties for administrative library purposes may not be used or disclosed for any other purpose.
Protection of staff, users, property? Who decides? Isn't that exactly the reason law enforcement generally ASKS for patron records? The library shouldn't decide when patron records should be turned over, and neither should law enforcement. A neutral, detached magistrate should decide, evaluating the context -- weighing both security and privacy. The magistrate will then issue court orders in some cases and deny them in others.
It seems that the problem could be better cured by defining library records more narrowly.