I noticed this rule after the housing crash. If one person was underwater on their mortgage, no one would blink. But, when hundreds of thousands of people become underwater, Congress started to get involved to (attempt to) provide relief.
It seems impossible to limit someone's exposure on Facebook, especially when any 3rd party will happily post a photo of your family member online. I also suspect that untagging a person on FB is analogous to FB's soft-deleting of statuses. The damage is already done.