Facebook may offer users unlimited gender options, but choosing anything other than "male" may have cost them a job. That's what three female Facebook users found when looking for work on the social network, a new complaint filed with the Equal Employment Opportunity Commission on Tuesday alleges. The complaint is backed by the American Civil Liberties Union and the Communication Workers of America and could be the first step toward a lawsuit against Facebook. Screenshots attached to the EEOC complaint show how Facebook lets advertisers target their messages to "single dads," "soccer moms," and a variety of other gender-based interests.