The DAO is a business owned by tokenholders who use their tokens to vote on business opportunities for The DAO to pursue with the hope of participating in the profit from those opportunities.

DAO tokenholders will likely be considered general partners if The DAO gets sued. As general partners each tokenholder (even if you own just 1) could be held legally liable for the entire debt. An enterprising Plaintiff's attorney might start off by subpoenaing an exchange with KNC requirements to get a list of tokenholders, then start adding the tokenholders with collectible assets to his lawsuit.