In those events, though, cable news was the main way we witnessed tragedy. Now, as we scroll through streams for updates sometimes clicking links which may have no warning that they lead to a photo of a man without legs. And it's not just images. Twitter's new product Vine is literally a loop of images, often replaying the explosions in a single click. As Whitney Erin Boesel eloquently explained over at The Society Pages:

Gone are the days when one had to watch an hour of TV news to see the same tragic explosion replay six times; gone, too, are the more recent days when seeing the same tragic explosion six times meant clicking “replay” five times on YouTube. Seeing this explosion six times takes only a single link click, and less than a minute of one’s time; in an hour, one could watch this explosion happen not just six times, but 600 times.

New media and platforms have changed the way we experience these events. "It’s the speed and ubiquity of these images that make one despair," wrote Philip Kennicot in his Pulitzer prize winning Washington Post essay "What are we losing in the Web’s images of suffering and schadenfreude?" But just how bad is that despair?

The term some use is media-induced PTSD. Christian Burgess director of Disaster Distress Helpline told the Wire that while there has been an uptick in calls to the hotline, about half of them are coming from people outside of the Massachusetts area. Those who have experience similar events, like the Virginia Tech shooting, which happened one year ago today, are particularly susceptible to feel anxiety, Burgess added. He has long blamed television's coverage for triggering a slew of mental health problems. "Not only does it risk worsening anxiety, depression, and substance abuse, but it can create new mental health concerns, particularly among people who may not have a support system in place, or who may be vulnerable to distress," he told the Wire.

Does social media, however, make it worse? Burgess says it certainly contributes to the overall distress, but he thinks it might be better than watching television. "I think there is a higher risk in more traditional forms of media beause its constant. It's sort of this static and continuous overview and replaying of the bombing," he said. "Because of the fleeting nature of social media, I think a lot of those images went under the radar or people intentionally didn't open them, which is good," he said. He also notes that people find other value in social media, such as community and communication.

But then when I told him I often clicked links of images that were more gruesome than I expected, he conceded that people have to be hyper aware on Twitter. "That's a good point. As a protective coping strategy, people who are feeling distressed should try and avoid that."