If you're a parent and you care about what kind of media your (underaged) kids consume, you wouldn't let them browse the web unattended or without a managed proxy.

The iPhone supports disabling the browser and other apps that can be used to access web pages (because these apps are flagged in the appstore) in their parental control settings. You can manually bypass the lock via a passcode if needed.

I think they're pretty serious in catering to the 'family' market segment.