class action lawsuit alleging that it can be easily bypassed. The manufacturer, Kaba-Ilco, made a design change in December 2010 that may or may not be related to the lawsuit, but may have made the lock more difficult to bypass.
This is an extremely popular mechanical code-operated lock. Regardless of the outcome of the lawsuit, there does appear to be a serious security concern. It may be bypassed with no damage, leaving no evidence that a bypass has occurred. The biggest problem may be that the bypass can be performed with limited knowledge and no particular skill.
If you have one of these locks (only the 5000 series is excluded from the lawsuit), your security may be at risk, especially if the lock is located on an exterior door.