Stop Enabling Sex Traffickers Act of 2017 (Sec. 3) This bill amends the Communications Act of 1934 to specify that communications decency provisions protecting providers from liability for the private blocking or screening of offensive material shall not be construed to impair or limit civil action or criminal prosecution under state or federal criminal or civil laws relating to sex trafficking of children or sex trafficking by force, fraud, or coercion. (Sec. 4) The bill amends the federal criminal code to specify that the violation for benefiting from "participation in a venture" engaged in sex trafficking of children, or sex trafficking by force, fraud, or coercion, includes knowingly assisting, supporting, or facilitating the violation. (Sec. 5) The bill amends the federal criminal code to allow a state attorney general to bring a civil action in U.S. district court on behalf of the state's residents if the attorney general believes an interest of the residents has been or is threatened or adversely affected by any person who knowingly participates in the sex trafficking of children or sex trafficking by force, fraud, or coercion.