It's not totally clear that this video was Peter Beinart's tipping point, but I thought this was interesting from Allison Hoffman's profile of Beinart in Tablet:
The essence of his case is that American Jews like him are as horrified to discover YouTube videos depicting the brutish realities of the Israeli occupation as they were by the realization that Saddam Hussein really didn’t have weapons of mass destruction.
Beinart focuses on one video in particular, of a Palestinian child screaming as his father is arrested by Israeli police on suspicion of stealing water from a settlement near his village. The little boy, Beinart writes, keeps howling, “Baba”—coincidentally, the same name Beinart’s own son, once unable to pronounce the Hebrew word “Abba,” calls him. This, he says, is what forced him to speak up against the occupation: his desire to prevent a day when he feels he cannot in good faith teach his young children, who have an Israeli flag hanging in their nursery, to be proud Zionists as well as committed Jews.
I remember that video well, I can still barely bring myself to watch the whole thing.
I agree with Beinart on the internet's role in getting out "the brutish realities of the Israeli occupation." It's a large part of what I think our job is here. I wonder how Beinart can watch the deluge of news from Israel/Palestine and still consider himself a proud Zionist? And, I wonder if that flag is still hanging in his children's nursery.