....would I lie down and take it if my children took my grandchilden away???
BLOODY HE!! NO!
I fight it with everything I had and take it to the highest court there is.
On what basis? You are not their guardian, nor even the parents guardian. Any law purporting to grant you the right would be abusive to common-law, and merely a wrong-headed generation of a law to enforce a generally good idea.
Except in extreme cases (ones which would cause consideration of guardianship), it is the parents full right and responsibility to determine the extent to which you may be involved. They are responsible for that judgement. With all due respect, I think involving the courts in such is, more than anything, being pissy.
I would hope that parents - even those that don't get along with their parents - give the chance for the bonds to grow between grandchildren and grandparents (for a multitude of reasons), but it is certainly not the place for the government to intervene between the parent and their child.