Twitter blocked conservative journalist James O’Keefe’s account on Wednesday evening, shortly after he tweeted that he was about to release new video about a candidate for the U.S. Senate.

Yes! Tomorrow our hidden cameras go inside a top donor fundraiser to see what a certain Senate candidate really thinks… #Election2016 https://t.co/la56fcoPyj — James O’Keefe (@JamesOKeefeIII) October 12, 2016

Shortly after that tweet, O’Keefe received a notice from Twitter that his account had been blocked for twelve hours. It is not clear why he was suspended. One possibility is that a slew of false complaints, potentially from fake “sock puppet” accounts, could have triggered an automatic response.

O’Keefe’s Project Veritas has released two videos thus far this week. The first, released Tuesday, showed Manhattan Board of Elections Commissioner Alan Schulman, a Democrat, attacking New York City Mayor Bill de Blasio’s municipal ID program as rife with fraud, leading to potential voter fraud. The second, released Wednesday, showed a Clinton campaign staffer in Florida who claimed that he could “grab” the “ass” of a female fellow campaign worker and he would not be risking his job.

Twitter previously banned Breitbart Tech editor Milo Yiannopoulos after he gave the new, all-female Ghostbusters film a negative review. Twitter cited racist tweets sent to Ghostbusters actress Leslie Jones by other people, though the actress herself has used racist language on Twitter.

On Tuesday, Prager University (PragerU), an educational project of conservative talk radio host Dennis Prager, reported that YouTube is restricting access to 21 of its videos. The videos included:

Are The Police Racist?

Why Don’t Feminists Fight for Muslim Women?

Why Did America Fight the Korean War?

Who’s More Pro-Choice: Europe or America?

What ISIS Wants

Why Are There Still Palestinian Refugees?

Are 1 in 5 Women Raped at College?

Islamic Terror: What Muslim Americans Can Do

Did Bush Lie About Iraq?

Who NOT to Vote For

Men and the Power of the Visual

Is America Racist?

Israel: The World’s Most Moral Army

Radical Islam: The Most Dangerous Ideology

The Most Important Question About Abortion

Why Do People Become Islamic Extremists?

Don’t Judge Blacks Differently

What is the University Diversity Scam?

He Wants You

Israel’s Legal Founding

Pakistan: Can Sharia and Freedom Coexist?

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. His new book, See No Evil: 19 Hard Truths the Left Can’t Handle, is available from Regnery through Amazon. Follow him on Twitter at @joelpollak.