One thing I will add here: TED audiences often come across as hopelessly . . . privileged.
Two caveats. First, I say this as someone who is no fan of the contemporary privilege-bashing rhetoric, through which large segments of the population are effectively removed from rational discourse through a kind of ill-conceived ad hominem. This is not to deny the reality of privilege, it's just that invoking privilege as a rhetorical tactic to shut down debate has a tendency to poison the well, strain social tensions, and hinder the unbiased and cooperative search for the truth.
Second caveat: I don't wish to engage in the widespread knee-jerk anti-TED ranting that is so common nowadays, and that was perhaps an inevitable outcome of the unprecedented success and popularity of the TED talk videos. A lot of the TED talks are grade-A presentations which manage the rare feat of being equally informative, amusing, and inspiring.
Okay, now for the critique. So often when I'm watching TED talks about very serious problems, including the one linked to above, the audience erupts into laughter at seemingly inappropriate moments. It's as if the audience's main goal is to be entertained or amused, and not to be informed or shocked out of their complacency. These people are hearing tales of poverty, disease, hardship, misery, and struggle, and their whole focus is on looking for any moment or a comment which can serve as an occasion for roaring with laughter.
Even as Ron Finley, the speaker in the above TED talk, was issuing his firm and serious call to action, the audience continued to merely laugh in response. What the Actual Fudge?! I get the impression that these wealthy TEDsters are so insulated from genuine hardship that they can't authentically empathize with the reality of others' suffering and struggles. Even their altruistic efforts come across as a type of half-hearted noblesse oblige, or (what's worse) as a type of pseudo-altruistic status-seeking, a type of social activist bling or a charitable feather in their cap. Perhaps I'm going too far here, but the question remains: HOW COULD THEY BE LAUGHING? HOW ON GOD'S GREEN EARTH COULD THEY BE LAUGHING?