Since your product is directed at minors, you need to be careful and a bit more conservative with signup and moderation. You need to get (and preferably capture) parent/guardian consents at login/reg/TOS acceptance for all persons under age 13. Capture IP address. Build in error if underage user attempts to proceed w/out parent/guardian approval. Moderate the "crowd sourced" feedback/inputs and shut down anything inappropriate, terminate any improper user behavior. Avoid permitting adults to contact minors directly via the crowd sourcing. Unfortunately, people with the wrong intentions toward children frequent sites aimed to help children. Avoid ads directed at selling things inappropriate for children, obviously. Have a clear, well-written TOS and enforce it. Maintain robust security around the data, especially that of your underage users.