Are you suggesting Facebook do that helpfully to aide their customers in avoiding mishaps? Or are you prescribing this be government ordained & required?
But Facebook is somehow how different? Why?
Oh right their business model doesn't work if they have to pay the costs associated with following government regulations.
I'm not feeling sympathetic.
I'm asking, are we wanting facebook to do it because it's ethical? Or are we wanting to legally require them to?
It's up to Facebook to take whatever internal steps they deem necessary to prevent that from happening. The government doesn't need to decide what steps need to be taken -- it only needs to care about the outcome.