I think this comment has been interpreted differently than it was intended...
To my mind, grandparents have no RIGHT to a grandchild. Parents have a responsibility to care for a child, but grandparents carry no such legal responsibility, and therefore should not be amongst those that have rights vis-a-vis children. More importantly, the very idea that children should be parented by committee is truly disturbing--if 2 people made them, it makes sense that no more than 2 people would parent them.
Further, if a parent has concluded for whatever reason that a relationship is not appropriate, then that is all that should matter, unless the parental rights are somehow compromised.
My in-laws are our of their minds. The very idea that they could petition the court to gave contact with my children (in spite of how badly they screwed up my DH and BIL) is appalling, at best. I, too, would go far, far away rather than allow those nutzo's in my DD's life.
As for Wishing on a star's comment about the police officer needing to know the applicable laws in his area... I understand where it might be coming from: If my MIL and I were screaming at eachother about my DD, and a police officer came to break it up, I would want to make sure that s/he was aware that grandparents don't have standing, as something really nasty could happen if the officer tried to enforce a law that didn't exist, and as another poster pointed out, it's not like they have a lawyer to bounce everything off of on the roadside.