One of the strongest legal protections available to pharmaceutical companies looking to recoup their substantial R&D and marketing costs for a new drug is a drug patent. This patent is so powerful because it allows the company to be the sole producer of a drug for a certain number of years without competitors being able to make a generic version. Some of the most profitable drugs in the country have been patent protected for many years and have allowed the producers to make huge profits. It is important to note that these protections are usually just for the US as most other countries impose price controls which leads to many patients questioning why there are such large differences in prices between countries. Indeed, there have been recent congressional hearings where Drug company CEOs have been drilled about this same issue. Another strategy that drug companies have used is to pay generic competitors millions to delay them from producing generic equivalents even after the patents have expired.