Armslist is a website that provides a place for private gun owners to sell guns to each other. It has several disclaimers excepting it from liability because it "does not certify, investigate, or in any way guarantee the legal capacity of any party to transact."
Demetry Smirnov met Jitka Vesel online (though not on Armslist). Vesel rejected Smirnov, and in response, Smirnov illegally purchased a gun through Armslist (illegal because, under federal law, a gun can't be transferred directly to someone from a different state; the seller was from Washington and Smirnov lived in Chicago).
Smirnov followed Jitka to a parking lot and killed her with the handgun he bought through Armslist. The Seventh Circuit ruled Tuesday that Armslist has no liability.