Facebook and Google have begun using automation to remove extremist content from their websites. This comes after online radicalism has seen a surge in the recent years.

Reuters reported that Facebook and Alphabet Inc.'s YouTube are two of the largest Internet companies that have started their efforts to eliminate violent propaganda from their sites. They are using systems that can block or rapidly take down Islamic State videos as well as other materials.

The controversial system was originally created to identify and remove copyright-protected content on video-streaming websites. The scanner looks for "hashes," which are a type of unique digital fingerprint assigned to specific videos.

Facebook and Google have not confirmed that they are using this controversial method. Several people who are familiar with the technology have revealed that uploaded videos can now be checked against a database of previously banned content.

"There's no upside in these companies talking about it," Matthew Prince, chief executive of content distribution company CloudFlare, said. "Why would they brag about censorship?"

New postings of a beheading or a lecture inciting violence will be cross-checked with that database and will be taken down. The sources did not discuss how much human intervention goes into reviewing and how the videos were initially identified as extremist.

"It's a little bit different than copyright or child pornography, where things are very clearly illegal," George Washington University's Program on Extremism deputy director Seamus Hughes said. He added that extremist content is a spectrum.

According to The Verge, there could be serious and unknown consequences with the upgrade of automated systems to suppress extremist content. Existing systems have been abused to suppress legal speech instead of focusing on suspected copyright and other violations.

Removal of extremist speech may also include more gray area rather than clearly-defined illegal content such as pirated media and child pornography. There would definitely be new, serious questions about these Internet companies as well as public and private corporations.