GREECE, NY (AP) - The pebble was tossed when a middle-school student in upstate New York posted a 10-minute video on his Facebook page.The video, showing four other seventh-grade boys cruelly taunting 68-year-old bus monitor Karen Klein, was quickly uploaded to YouTube.And the ripples began.Millions of viewers from around the world watched her humiliation. There were cries of indignation and sympathy, retribution and recompense. Through posts on social media and the user-generated news site Reddit.com, word spread geometrically, leading to a fund drive that began with a modest goal of $5,000 to help Klein take a nice vacation and scrub the foul memories of the last days of school from her mind.By Friday afternoon, the drive had sailed past $550,000, with donations from more than 25,000 people.Even in an increasingly connected, fast-moving world of information flow and echo, the response to Klein’s plight is a stunning example of the power of people in the new, Me-Media era.“Oh, my God,” Klein told The Associated Press in an interview Thursday, when the total was around $370,000.