[CA_soon_gone]

From the article:

Joshua Koskoff, a lawyer for the families, argues there is an exception in the federal law that allows litigation against companies that know, or should know, that their weapons are likely to be used in a way that risks injury to others.

Why would anyone write this into the law? It's a weapon, that's its job.

[Velvet_Jones]

That's because it's NOT written into the law. That's the way he's interpreting the law, but he's being extremely creative with how he's doing it. In effect, he's doing what the law says he can't do, but because he's expressing it differently from how things are spelled out in the text of the law he says it's ok.

FYI, text of the law can be found here