For the 1 billion monthly users who rely on Facebook’s classifieds behemoth, this notification is the digital equivalent of having your storefront padlocked overnight. Whether you are a suburban mom selling a stroller or a vintage furniture flipper making rent, a Marketplace block is not just annoying—it is existential.

Yet, the gatekeeper is famously erratic.

Mark’s story is the archetype of the “shadow block.” Unlike a permanent ban for selling guns or live animals (which are legitimately prohibited), most users are snagged by the platform’s overzealous AI.