Diaspora is the Privacy Aware Open Source Social Network. Diasp.org is an open Diaspora pod and is user supported.
This is a social networking site. It may or may not be suitable for young children. It is a good site. No bad stuff like malware, phishing attacks, etc.
Well managed and run, a wonderful alternative to Facebook. No privacy risks or invasions, and lots of options to start your own server too!
The diasp.org diaspora* pod. "Safe" here depends on who you follow and what you view, like any other social network.