Arizona immigration law SB1070 is a controversial piece of legislation that requires all people within the state to carry identification proving their legal immigration status at all times. This law allows police to question and detain anyone they suspect is an illegal immigrant. The police can then contact federal agencies to prove a person's identity or deport them if they're in fact an illegal immigrant. Before this law, only federal officials enforced immigration laws. Arizona is the first state to give its law enforcement officers this power.