A person who reveals, uncovers, or discloses something hidden, secret, or shameful to the public.
From 'expose' (Latin 'ex-' (out) + 'pausare' (to spread out)) + '-er' (one who). The agent noun indicates a person performing the action of exposure.
Modern exposers are often whistleblowers risking careers and safety—Edward Snowden exposed NSA surveillance, Frances Haugen exposed Facebook's algorithm, and they're part of a tradition going back to Daniel Ellsberg's Pentagon Papers.
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