The Shakespeare scholar Jonathan Bate, who began working on a biography of the former poet laureate in 2010, said he was surprised that the estate has barred him from private archives, asked that he return photocopies of privately held documents, and withdrawn his right to quote extensively from the poet's work – described by the professor as "an essential aspect of serious scholarship".
That's right. A respected scholar (and Bate is extremely well-respected) has been legally barred from quoting archives that are housed in the national library. Because Hughes's heirs have inherited his copyright. This has become a standard tactic used by writers' families to suppress facts.
In 1987, J. D. Salinger sued Random House and successfully blocked a biography of him, because it used letters that Salinger had sent to people. Under earlier copyright law, those letters would have been fair game, but under current law the author and his heirs have a right to control just about everything he's touched. So Salinger could prevent biographers from using his letters. This is so extreme that when the biographer paraphrased what he'd seen in the letters instead of quoting them, Salinger still managed to sue and win. It's not that Salinger was suppressing lies about him. After all, he had written everything in those letters himself. Copyright law allowed him to keep the truth from the light of day.
Later, James Joyce's family forced the Joyce scholar Carol Shloss to remove nearly all the archival evidence from her book on the role Joyce's daughter Lucia played in her father's work. Shloss then got savaged by reviewers for making claims that she apparently couldn't back up with facts. Actually, Shloss did have the documented facts, she just wasn't allowed to use them.
Shloss eventually won the right to republish her book with the actual evidence in it, but it took years and years of suits and counter-suits. And even if that sounds like a happy ending, it's not. If a publisher knows that publishing your book is going to mean years of expensive litigation, it is not going to publish your book, even if you have a good chance of winning in the end. The threat of legal action by estates is enough.
Here's the joke: this law can only be used to prevent a scholar from telling the truth. The estate only holds the copyright of a letter or diary because their ancestor did actually write it. A writer's heirs could never sue a biographer for libel. Dead people cannot be libeled. But a writer's family can come after your house for quoting that writer accurately.
Worse still, families can use the threat of withdrawing permission in order to demand that biographers turn out the biographies that the family wants. If you don't make Grampa look the way they want Grampa to look, they can kill a book that you've already spent years working on. The law is abused to create propaganda instead of scholarship, to force biographers to turn out distorted, hero-worship versions of the truth. Society gains nothing from that. The law as currently enforced actually promotes falsehood and dishonesty.
And please remember: this law does not only apply to writers. It applies to everyone, including public figures. Everyone's personal letters, diaries, and journals are copyrighted until 75 years after they die. Which means that public figures' heirs will also be free to cherry-pick which historical evidence about them gets published, and what can never see the light of day.