Judy Blume and fellow authors and readers have rallied behind Laurie Halse Anderson's acclaimed young adult novel about the rape of a teenager, Speak, following a call to ban it from schools in Missouri.

As libraries and bookshops across America highlight the dangers of censorship with Banned Books Week, their annual celebration of the right to read, a campaign backing Anderson's book has taken wing across blogs and Twitter. The widespread support for Speak follows an op-ed from Wesley Scroggins, a professor at Missouri State University, in Missouri's News Leader, which said the book "should be classified as soft pornography" and called on parents to "get involved".

"How can Christian men and women expose children to such immorality?" he wrote. "This is unacceptable, considering that most of the school board members and administrators claim to be Christian."

Scroggins also complained about Kurt Vonnegut's Slaughterhouse-Five ("This is a book that contains so much profane language, it would make a sailor blush with shame. The 'f word' is plastered on almost every other page. The content ranges from naked men and women in cages together so that others can watch them having sex to God telling people that they better not mess with his loser, bum of a son, named Jesus Christ"), which has now been removed from the district's curriculum, and about Twenty Boy Summer by Sarah Ockler, which is being reviewed.

"The fact that he sees rape as sexually exciting (pornographic) is disturbing, if not horrifying. It gets worse, if that's possible, when he goes on to completely mischaracterise the book," wrote Anderson on her blog, which she said has now been viewed by tens of thousands of people. A hashtag on Twitter, #speakloudly, became one of the most popular topics on the micro-blogging site last weekend, and vehement anti-censorship campaigner and author Judy Blume described the situation as "outrageous" and brought it to the attention of the National Coalition Against Censorship, which is now investigating.

"EVERYONE spoke loudly. Thousands of people linked to my post and recommended it on Facebook and on their own blogs. One social media expert said that, based on the Facebook recommendations alone, he estimated that 350,000 heard about the banning," said Anderson, a finalist for the National Book award in the US for Speak, her debut novel. "As if all of that weren't astounding enough, many readers posted their own stories about being silenced, about being sexually assaulted, about speaking up, about being a Christian tired of seeing other Christians invoking the Bible as justification for censorship, and about how Speak changed their lives."

One of the readers to speak out was UK children's author Lucy Coats, who was prompted by the uproar to buy Anderson's book and found it raising a memory of a sexual assault from her own childhood, which she felt moved to share, for the first time since it happened 40 years ago, on her blog.

"I read Speak in one sitting and it just unlocked something which had been hidden in me for years and years ... I think it's something about the silence of the girl in it, how she doesn't feel she can speak out about it because she's too scared, and I suddenly thought yes, that's how I felt, I was too frightened. [And] I thought 'I'm a writer, I can either sit on it, or stand up for all the people who can't'," Coats said today. "The response has been amazing on Facebook and Twitter, and I've had so many private emails from women telling their stories, all saying they've not been brave enough to speak out in public but that I've given them comfort. It has been an exorcism in public."

Coats called Scroggins's comments about Speak "very disturbing" and said that issues such as teenage rape "need to be talked about". "Perhaps you wouldn't give [Speak] to a young girl but teenagers need to know about this. So many people who've read Speak have said 'it happened to me, it helped me through it'. It's about letting children know they aren't alone, that these things do happen but they can recover from it," she said. "Banning books is about fear and I just hate that [but] a lot of people are speaking out against it and telling [Scroggins] to piss off, which is important … It's ignorance and fear and as writers we have to try to lift the veil of ignorance and fear."