When the "media" tried to show the speeches, they were sued.
"Eyes on the Prize" (said by many to be the most important civil rights documentary of all time - showing historical footage from the period) isn't shown publicly anymore and its creator was sued.
How can one write about a subject without using reference material of some sort, knowing that use of that material may very well get them sued?
You really think it's some vast conspiracy?
If King remains a one-dimensional grainy black-and-white figure who utters the same sunny sound bite year after year until it's a cliche, it's because news networks won't pay for more, and researchers have been kept from delving deep into his papers to tell us something new about the Martin Luther King the man, not the statuette.
And his family wants it that way.