Anonymous is a decentralized international activist/hacktivist collective and movement widely known for its various cyberattacks against several governments, government institutions and government agencies, corporations, and the Church of Scientology. Anonymous originated in 2003 on the imageboard 4chan representing the concept of many online and offline community users simultaneously existing as an anarchic, digitized global brain or hivemind. Anonymous members (known as anons) can be distinguished in public by the wearing of Guy Fawkes masks in the style portrayed in the graphic novel and film V for Vendetta. However, this may not always be the case as some of the collective prefer to instead cover their face without using the well-known mask as a disguise. Some anons also opt to mask their voices through voice changers or text-to-speech programs.
Chroma key compositing, or chroma keying, is a special effects / post-production technique for compositing (layering) two images or video streams together based on color hues (chroma range). The technique has been used heavily in many fields to remove a background from the subject of a photo or video – particularly the newscasting, motion picture and videogame industries. A color range in the foreground footage is made transparent, allowing separately filmed background footage or a static image to be inserted into the scene. The chroma keying technique is commonly used in video production and post-production. This technique is also referred to as color keying, colour-separation overlay (CSO; primarily by the BBC), or by various terms for specific color-related variants such as green screen, and blue screen – chroma keying can be done with backgrounds of any color that are uniform and distinct, but green and blue backgrounds are more commonly used because they differ most distinctly in hue from most human skin colors. No part of the subject being filmed or photographed may duplicate the color used as the backing.