The Middle East Forum continued its campaign for tech companies to stop politically censoring material, warning on Tuesday about the recent trend of the suppression of anti-Islamist information published by moderate Muslim activists.

The Philadelphia-based think tank calls on the public to email information on documenting this trend, particularly related to the censorship of anti-Islamist content, at: censorship@meforum.org. “If you have screenshots or other evidence, that is best, but we are also happy to hear anecdotal evidence,” the forum said in a statement.

It has previously written about Google’s collaboration with The New York Times, The Guardian and Wikipedia on ways to automate censorship of “offensive” content. YouTube and Google are now following Twitter’s practice of “shadow-banning,” defined as hiding or down-ranking content that tech companies find politically unpalatable.

The practice by these influential companies of deleting posts and suspending accounts is becoming more common.