I don't have much to add about the Boston marathon bombing itself that isn't being said better elsewhere. It's sad and disturbing and I hope the authorities can get to the bottom of it quickly.
But I do want to comment on one small part of the reaction to the bombing; specifically, the reaction on Twitter. As you might expect, the earliest reports were accompanied by an explosion of Twitter activity. As you may not have suspected, a huge portion of this early response consisted of Twitter personalities cautioning others not to spread misinformation and chiding anyone who appeared to be tweeting unconfirmed reports.
It's true that social media outlets like Twitter are very frequently a hotbed of misinformation in a crisis. A fake or mistaken report can spread like wildfire. It would be generous to say that Twitter is only 99% echo chamber; there are simply very few obstacles preventing any information in circulation, regardless of truth or falsity, from reaching millions of people, if retweeters deem it sufficiently newsworthy. Caution is always advised when reading Twitter, advice that goes double in a crisis.
But social networks are hardly alone in being easily duped. One only has to think back to Newtown to see staid news outlets struggling to sort between rumor and reality, and failing badly. On 9/11, it was widely reported that the State Department had been bombed; social networks as we know them did not even exist.
You might say this indicates that all news outlets, whether crowdsourced or centralized, should exercise similar degrees of caution, checking rumors before reporting them. I think this would be an error. Traditional outlets specialize in factchecking rumor, and so they should factcheck diligently. Twitter specializes in something else altogether: gathering vast quantities of information very quickly, and disseminating it broadly. In doing so, it might serve as a vector for misinformation, but it can also function a powerful sieve for accuracy. Twitter rumors explode, but within ten, twenty, or thirty minutes, generate denials or rebuttals, which explode in an equally uninhibited fashion. The reason rumor can outpace verification in traditional media is that the latter is tied to old-fashioned factchecking process that takes time; on Twitter, both truth and falsehood are equally fleet-footed.
This is pretty much Twitter's comparative advantage over traditional sources. It's an advantage that would disappear, however, if everyone on Twitter passively refused to retweet anything that had not yet been confirmed by CNN or the NYT. In fact, doing so would transform social media into nothing more than a shadow of the old media establishment. Why read it at all, when you could get the same information by turning on the TV?
So I wish the old media would worry a little less about Twitter's capacity to spread rumors, and more about confirming the ones that crop up. Today is a strong case study: some of the things reported on Twitter turned out to be true (so far), others false (so far). Some things--e.g., the confusion over a fire at the UMass library--appear to have reflected genuine confusion among authorities. But because I was following along online, and didn't ignore every tweet that lacked official confirmation, I knew the basic shape of events long before a TV viewer would have. Ultimately, we'll probably all know exactly what happened; widespread participation in the organic process of fact discovery only speeds that moment.