Red-baiting, also known as reductio ad Stalinum and red-tagging, is an intention to discredit the validity of a political opponent and the opponent's logical argument by accusing, denouncing, attacking, or persecuting the target individual or group as anarchist, communist, Marxist, socialist, Stalinist, or fellow travelers towards these ideologies. In the phrase, red refers to the color that traditionally symbolized left-wing politics worldwide since the 19th century, while baiting refers to persecution, torment, or harassment, as in baiting.

Red-tagging in the Philippines is the malicious harassment and blacklisting of individuals or organizations critical or not fully supportive of the actions of a sitting government administration in the country. These individuals and organizations are "tagged" as either communist or terrorist or both, regardless of their actual political beliefs or affiliations. It is a type of incitement and has pernicious effects on its targets. Red-tagging may be performed by either security forces, government officials or shills.