Any person who uses, has in their possession, distributes, or grows marijuana in the United States is committing an illegal act under Federal law. Marijuana is a controlled substance, and having it on your person is a chance many people take, even though most of them are well aware of the laws in the state where they live. Many states have criminalized possession of marijuana, and a few have taken the bold step of passing laws stating that if a person has a written or oral recommendation from a physician which tells them that marijuana would help the type of illness they have, then it is legal for them to possess the drug. This is known as Medical marijuana, and it is hoped that all 50 states will soon pass similar laws. Those approved would be given ID cards stating that it was legal for them to be in possession of marijuana. That said, possession of marijuana is still an illegal act more most people who live in the United States.