The fight over a controversial pair of Internet piracy bills reflects a turning point in the way interest groups influence policy, observers say. A realm that was traditionally the domain of lobbying firms and business associations is being forced to confront a new power structure of Web companies and Internet activists. "I think it is an important moment in the Capitol. Too often, legislation is about competing business interests. This is way beyond that. This is individual citizens rising up," said Rep. Zoe Lofgren, D-Calif.