When bears have learned to open rigid canisters, the manufacturers have changed the designs to resolve the situation. That's working with the park service. When bears opening ursacks got the ursack acceptance cancelled, the Ursack company filed a law suit and lost. What is there to work with when a company won't fix their design? This is the USA and business models based on substituting law suits for competent design exist, but there's no reason anyone should respect them.
Dale B. Dalrymple
