The responsibility is not Facebook's, but rather the news organizations that reported early rumors and reports as facts. IANAL, but i would expect that they potentially face libel suits for defamation of character.
In this situation, Facebook is merely a modern day phone book (albeit vastly more robust and complex). It is the news organization that bears the responsibility of gathering, checking and publishing verified facts. That's called reporting.
To be fair, this was not a rumor...their police sources had been mixed up because the shooter died with his brother's ID....that is the explanation, anyway...so much of this story has been contradiction after contradiction that it almost seems like someone in the police department is a 4chan troll
News organizations are generally irresponsible. Remember the Zaniada Gonzales debacle? A poor woman was nearly lynched for having the same name as an imaginary person dreamed up by some child killer.
I agree that Facebook has no legal responsibility here, but the responsibilities they have willingly to take on in the past does create an level of expectations in the userbase. The userbase is completely within their rights to try and exert social pressure on facebook.
If Facebook chooses to actively prohibit adult content being shared between two adults, and monitors the content of private chat conversations, why shouldn't it remove this type of content when it comes to their attention? Is it unreasonable for users to expect them to do that?
I don't think you can even remotely refer to it as a phone book and this is not to be pedantic. With Facebook, you communicate, albeit mostly inane drivel that passes for "thoughts" but you can communicate. In fact, you can use Facebook to whip people into an angry frenzy, directly, rather than just use it as a directory to call people indirectly organize a lynch mob. In some ways, you could say the harassment is actually occurring on Facebook.
If only there was some kind of social platform where Facebook employees could share information like this and it would end up being forwarded to the appropriate people...
Facebook has the ability to look for trends and spikes in activity. If fb start seeing lots of new pages and groups springing up called "$name is a killer" then you can know something is going on
In this situation, Facebook is merely a modern day phone book (albeit vastly more robust and complex). It is the news organization that bears the responsibility of gathering, checking and publishing verified facts. That's called reporting.