There is a legal reason most of these are for 13+. Because of the Children's Online Privacy Protection few web-sites want to enroll children who are younger. Most popular online games officially require kids to be 13 (although many kids just lie about their age and use them anyway -- like facebook) or ask that parents sign their kids up.

http://en.wikipedia.org/wiki/Children%27s_Online_Privacy_Protection_Act

Last edited by bluemagic; 05/11/14 09:51 AM.