Harvard law professor emeritus Alan Dershowitz spoke out on Wednesday to react to Donald Trump’s Big Tech lawsuit against Twitter CEO Jack Dorsey and Facebook CEO Mark Zuckerberg.

After saying that he is “deeply involved” in the issue of censorship and was asked to be an expert witness, Dershowitz predicted that the lawsuit “will shake things up considerably.” He added that censorship by big tech is “unacceptable” and “inconsistent with the spirit of free speech.”

“As you know, I wrote a book about that exact subject, ‘The Case Against the New Censorship: Protecting Free Speech from Big Tech,’ so I’m deeply involved in this issue, and I was also asked to be an expert witness. And I did submit an affidavit for this lawsuit, so I’m not simply an observer,” Dershowitz stated. “This is a very, very important lawsuit. What’s going on with high tech is unacceptable. It’s inconsistent with the spirit of free speech that underlies our First Amendment.”

“This is a complicated case because, as the president pointed out, and as Pam Bondi pointed out, and as the others pointed out, these are not just ordinary private companies,” he added. “They have special exemption under Section 230, and therefore they partake of some kind of government action, and the courts will have to parse this issue. How much of what they do is private? How much of what they do partakes of being public?”

“What we don’t want is the government telling private companies what they can say and what they can do,” Dershowitz concluded. “That would be wrong, but we don’t want these crazy public enormous monopolistic companies to be restricting our free speech. The current situation is unacceptable, and this lawsuit I think will shake things up considerably, though I can’t predict in the end how it will come out.”

Trump announced his Big Tech lawsuit earlier in the day on Wednesday.

“I stand before you this morning to announce a very important… development for our freedom and freedom of speech,” Trump said as he announced the lawsuit, according to Fox News. “In conjunction with the America First Policy Institute, I’m filing, as the lead class-action representative, a major class-action lawsuit against the big tech giants, including Facebook, Google and Twitter, as well as their CEOs.”

“There is no better evidence that big tech is out of control than the fact that they banned the sitting president of the United States earlier this year,” Trump added. “If they can do it to me they can do it to anyone.”