回复：我是H1B, 可以在美国开公司吗? 别人给我私人支票, 要上税吗?

You are supposed to pay tax even you obtain it illegally such as selling drugs. If you got caught for illegal activities, then at least you are not going to be charged for tax evasion. But IRS is separate from the immigration services, they are not going to report you for illegal activities.