Our children are constantly on-line. Even down to pre-schoolers. A great resource for parents (and grandparents) to help understand the proper precautions for children (and to understand the things that are available for children), is the Keep Safe Coalition site called www.ikeepsafe.org .
There are resources for parents and children to understand how to keep safe on the ‘net. This is a place that every parent should look at with and for their children.