One of the big healthcare reform battles is over a single provision in the 1,000-page law: that we must buy health insurance. And if we don't, we pay a fine. It's angered a lot of people. Congress, some say, doesn't have the right to force us to buy anything. If it does, it's infringing on our individual rights. Like all arguments, this one has another side. Those in favor of healthcare reform say the requirement to buy insurance will keep costs down for all of us. Without it, they say, only sick people will buy insurance. And we need healthy people paying into the system so costs are spread out among more of us. They also say that if you go without insurance and then get sick, the rest of us have to pick up your tab either through taxes or higher medical costs. The argument over what's called "the individual mandate" or "individual responsibility" is the key point in the lawsuits that states have filed to try to repeal the law -- or at least parts of it.