IWF (Internet Watch Federation) has started to filter out major file hosts such Megaupload & Hotfile.
"The Internet Watch Foundation is an organisation that prevents access to child pornography websites. If a website is hosting multiple things (ie, the majority of legal content and one page of suspected illegal content) then the proxy system is deployed. " source - click here
"The Internet Watch Foundation is an organisation that prevents access to child pornography websites. If a website is hosting multiple things (ie, the majority of legal content and one page of suspected illegal content) then the proxy system is deployed. " source - click here