The Internet is just one more way that, on nights like Monday night, the whole world is watching.
Obviously misinformation is a challenge for any criminal investigation, much less a racially charged on that becomes world news. That's why you have a grand jury process - a lengthy and involved one in this case - to sift through the evidence.
And yes, social media can be where people go to repeat what they want to hear or are already inclined to believe, on all sides. "Social media," like any media system, is really just a fancy description for a lot of people connected and communicating. It's as good or bad as the people themselves.
But we're better off having social media, especially in situations like Ferguson's. When the first round of protests broke out in August, it was through social media that reporters first got out the news of their arrests and tear-gassing by riot police, some of whom ordered the reporters - as well as protesters in the crowds - to "stop videotaping" with cameraphones. After the grand-jury announcement, voluminous records from the investigation went up online, for the hive mind of social media to begin poring over and analyzing.