The term 'TAKES ACTION AGAINST' can be summarized as 'suing', which is a legal action taken by one party against another in a court of law. The four-letter solution for this term is 'SUES'. This is when a plaintiff (the person or entity filing the lawsuit) brings a civil action against a defendant (the person or entity being sued). The purpose of the lawsuit is to seek compensation for damages or to compel the defendant to take some action.