A law banning the sale of sex toys was struck down by a federal judge as violating privacy rights. ''The fundamental right of privacy, long recognized by the Supreme Court as inherent among our constitutional protections, incorporates a right to sexual privacy,'' Judge C. Lynwood Smith Jr. of federal District Court in Birmingham said on Wednesday. Judge Smith said the state did not prove that it had a legitimate interest in banning the sale of sex devices for use in adults' private consensual relationships. Attorneys for the state claimed instead of resorting to sex toys, that women should just have sex with their brothers.