Sorry EMI Music Publishing has blocked you from seeing Martin Luther King's I have a Dream Speech. Sadly our society's historically important moments are not considered something people should see to the copyright cartel and those they pay in congress to push their agenda. I can't imagine Martin Luther King would have desired to restrict those seeing his message. I do understand that it isn't uncommon for those that gain the rights to material created by great people seek to cash in rather than to promote the work the great person did (and still would be doing if they could).
Today is Martin Luther King Day in the USA. Watch the entire I Have a Dream Speech.