Here's the biography of Sean Parker in Vanity Fair:
http://www.vanityfair.com/cultur...Here's excerpt containing the Plaxo story:
Eventually, Parker and some partners managed to land some seed money from Sequoia, the prestigious Silicon Valley venture-capital firm. The company, named Plaxo, opened its doors that November. In short order it became the most famously annoying service on the Internet, peppering innocent Web users with requests to correct their entry in their friends’ address books. For the irreverent Parker, this was a virtue—a triumph of viral marketing. But disgrace soon followed. Parker’s unreliability began to grate on his colleagues and the company’s investors. Sometimes he didn’t show up for work. By early 2004 he was fired. The company’s board later hired a private investigator in a retroactive attempt to look into various rumors, including whether Parker had been providing drugs to other employees. Parker—who calls the accusations “ludicrous, a smear campaign”—was again on the street, and broke.