The U.S. Supreme Court appeared split on Tuesday as it considered a case testing state limits on data mining. At issue is whether states can bar the buying, selling and profiling of a doctor's prescription records without the physician's consent. Government regulations require pharmacies to keep records of all doctors' prescriptions. In most states, pharmacies can and do sell these records to data mining companies -- companies that in turn sell the information to drugmakers for use in targeted sales pitches to doctors. When doctors in Vermont found out their prescription records were being sold this way, they went to the state Legislature, and the state enacted a law barring the practice. The data miners and the pharmaceutical industry challenged the law in court. They contend it is unconstitutional because it makes it more difficult for drugmakers to identify doctors who would be good prospects for sales. But Vermont contends the law constitutionally allows doctors to decide for themselves whether information about their prescription habits can be sold to data miners.