Dartmouth College computer science professor Hany Farid — using funding from Microsoft Corp. — has developed technology to help scrub extremist content from the internet.

Working with the nonprofit think tank Counter Extremism Project, Farid built software capable of identifying and tracking photo, video and audio files, even if they’ve been altered. The software, unveiled Friday, would allow websites such as Facebook Inc. to automatically catch flagged content and remove it or prevent it from being uploaded.

On a call to discuss the technology, Farid, who is also a senior advisor to the CEP, said his software would allow companies to automatically remove posts that violate the sites’ terms of use. He also said deleting the content is not a freedom of speech issue because the companies have the right to dictate what’s suitable.

“We allow them to do it fast, accurately, automatically,” he said.