Without diving in even as far as you have, my main problem with the proposed law is that it would remove FB's liability in complying, so the default will be to

Without diving in even as far as you have, my main problem with the proposed law is that it would remove FB's liability in complying, so the default will be to simply hand over any information related to any investigation. "Opt-in" is the obvious answer for a corporate entity wishing to mitigate its financial liability.