Links need to be approved, but why?

[papajchris]

Why do links needs to be approved especially links to safe sites such as cnn, best buy, walmart, or w/e the heart desires but is a well known site? I go on many forums and no other forums forces it's members to get their links approved. Yet there is little abuse of people trying to post porn and viruses. If that is what the mods are afraid of, why not like i said have links to trusted sites be okay to be auto approved. If someone links to CNN, or youtube, the site won't show anything legal as it's moderated and written by the people who own these sites.