How do we trust the firmware from a company that had backdoors in their product open to the world? The first time there was a lot of 'well any multi-team produc

How do we trust the firmware from a company that had backdoors in their product open to the world? The first time there was a lot of 'well any multi-team product devs could screw up..' but the second time it was exposed they knew of the open exploit for quite some time and chose not to patch it right?