A very important decision (Daniel v. Armslist, Inc.), but I'm too slammed to discuss it in detail -- fortunately, Prof. Eric Goldman (Technology & Marketing Law Blog), who is one of the top experts on § 230 immunity, has a thorough analysis. (Recall that § 230 is what lets this site function without fear of liability for allegedly libelous, privacy-invading, or negligently dangerous material posted by commenters, what lets Yelp function without fear of liability for similarly tortious reviews posted by its users, and what lets Google function without fear of liability for tortious material on sites that it searches. Nothing in § 230 is gun-specific or even advertising-specific, so any decision that allows liability against a gun ad site could allow liability against sites that are supposedly designed in ways that facilitate libel, or a wide range of other tortious behavior.)
The case relates to a shooting in the Milwaukee area that killed four people and wounded four others. The shooter found the seller of the gun and ammo on Armslist, an online marketplace for such things, even though the shooter was subject to a court order banning him from owning a gun. (The maxim "if guns are outlawed, only outlaws will have guns" seems vaguely apropos here). The shooter and seller consummated the transaction offline, so Armslist functioned as an online classified advertising service....
Some of the complaint's key allegations:
[*] Armslist made it easy to search for private sellers, who–unlike licensed dealers–do not have to conduct background checks on buyers. Thus, Armslist "is designed to enable buyers to evade state waiting period and other legal requirements"
[*] Armslist allowed users to flag problematic content but "expressly prevented users from flagging content as purportedly criminal or illegal"
[*] Armslist warned users not to engage in illegal activity but didn't provide "guidance on specific laws governing firearm sales or the care that should be used in conducting such sales" [LAW GOVERNING LAWYERS ALERT: it would potentially constitute the criminal unauthorized practice of law for Armslist to provide "guidance" to its users about specific laws]
[*] Armslist didn't require account registration and thus encouraged anonymity
[*] [T]here is evidence that many buyers wanted to buy from private sellers, especially in states that require licensed dealers to conduct background checks of buyers. A survey indicated that "67 percent of private online sellers in Wisconsin are willing to sell to a person they believe could not pass a background check."
The court summarizes (emphasis added): "Daniel's theory of liability is that, through its design and operation of website features, Armslist's actions were a cause of the injuries to Daniel."
As you know, courts have repeatedly and emphatically shut down plaintiffs' efforts to work around Section 230 by saying they are suing for the defendant-website's "design and operation." [But the Wisconsin court disagreed with those courts.]