Since there is a feature to ignore users, which is /ignoreadd username, why not just use that if you are offended by what you see?
Furthermore, parents are bound by the Terms of Use, http://ubi.com/US/Info/Info.aspx?tagname=TermsOfUse and need to take responsibility for what their children do on the Internet.
See Sec. 4, ACCESS AND TERMS SPECIFIC TO MINORS
I appreciate what you want here, but in my opinion you are being unrealistic.





