A cyberterrorist is someone who uses the internet to damage computer systems, usually to push a political idea or to frighten a government, a company, or the public. The harm is meant to shock, not only to steal. News, police, and governments use this word; it sounds heavy and official. A thief who breaks in for money is a cybercriminal, not this. Though actually, after a big hack, headlines sometimes call the person a cyberterrorist even when the aim was cash, not politics. You will also see cyber-terrorist with a hyphen, or cyber terrorist as two words.