Previouslynot letting children receive email from Gmail because they hide the source IP address making it easier for bad guys to hide. In contrast, the free webmail services from Yahoo and Hotmail do not hide the source IP address.
In response, Google pointed me to an item at the Gmail help center called Harassment from a Gmail user. Below is what Google has to say regarding harassing emails from a Gmail user.
"... if you feel that you are in danger, we suggest contacting your local authorities.
Because message headers and senders can be spoofed using a variety of means, we're unable to take action on any user without further verification. In accordance with state and federal law, it is Google's policy only to provide information about a specific Gmail user pursuant to a valid third party subpoena or other appropriate legal process.
We apologize for any inconvenience, and we're sorry that you're receiving such messages."
Google won't take complaints directly from harassment victims and they omit contact information for law enforcement agencies. Not particularly comforting.
Judge for yourself, but I think this validates my prior suggestion not to let children receive email from Gmail users. The source IP address can not directly identify someone, (for more about this see) but victims of harassment are far better off with it than without it.