What do you do when you witness a child being verbally abused in public?

Last week I was approached by a librarian who wanted to discuss a workshop idea she had and would I be interested in presenting it.  She and her colleagues had been discussing the difficulty they face when a parent comes into the library and begins to verbally or physically abuse their child.  The question is, she said, if we stand by and do nothing, we feel as though we’re condoning the behavior but we’re not in a position to present a lecture on parenting as they’re standing in the library with their child.  It’s a public place and they’ve come to borrow books.  The librarians want to know how they can effectively handle what they see as a delicate situation.

My first response to the librarian is that what she’s describing is something I struggle with myself.  If I witness a child being verbally attacked or demeaned in public, I want to say something.  It turns my stomach .  Everything in me wants to hug the child and tell them they don’t deserve to be treated that way. I agreed with her that standing by and doing nothing doesn’t seem right either.  She wasn’t talking about the kind of abuse we know we have a duty to report.  In that case, here in Canada, we are obliged to call the Ministry of Children and Family Development. It’s that grey area we’re talking about.  It doesn’t legally fall under the category of abuse but we know it’s not a fair and loving way to treat an innocent child. 

One thing I know for sure is parents who verbally attack their children do it because they don’t know what else to do.  In the majority of cases, they were treated exactly the same way so it’s all they know.  Their own parents were also treated that way.  They’re simply repeating a pattern and have never been shown or taught how punishment of this sort can be detrimental to a child’s well-being. 

What is the correct ethical and moral  response to a parent who is demeaning and verbally attacking their child in a public place?  If we believe it to be a cultural norm, do we just accept it as that or do we educate?  When is it appropriate  to intervene?  Should we show compassion to the parent who might be just having a bad day?   We’ve all heard “It takes a village to raise a child”.  What are your thoughts?