In the past, Facebook (FB  ) has been criticized for allowing landlords to more easily discriminate based on race and for employers to discriminate on the basis of age. Facebook now faces charges of assisting in discriminating against female applicants in recruitment campaigns that target male job applicants only.

A group of women filed a formal complaint with the federal Equal Employment Opportunity Commission this past Tuesday. They were supported by the Communications Workers of America and the American Civil Liberties Union. According to the group, employers who advertised on Facebook seem to have taken advantage of the platform's targeting technology, enabling them to withhold their advertisements from the view of female users. The jobs being advertised include truck driving and window installation positions. The charges against Facebook were filed on behalf of all female job searchers who made use of the platform in their search in the past year.

According to an expert witness, the aforementioned campaigns appear to flout federal law. Recruiting firms are forbidden from discriminating on the basis of a number of protected categories, one of which is gender. Furthermore, certain state laws also forbid assisting in discrimination so Facebook cannot get away with the argument that they were merely the passive tool for the job ad posters. Experts claim that Facebook's adjustable technology filters and settings render it closer to an employment agency than to an inactive medium of presentation.

The legal team on the case first spotted the signs of discrimination by overseeing a group of workers who searched for jobs via Facebook and opened many advertisements. For each ad that a job seeker opens, Facebook sends a disclosure to explain why they were shown that ad. The ads that were deliberately targeted at men were accompanied by a disclosure that explained exactly that.

Three of the employers who placed the ads declined to comment on the complaint. Upon further investigation, the lawyers discovered that the companies did not create similar ads for women. Some companies promised to stop airing the ads targeted at men only, and others argued that the Facebook ads targeting men were only a single facet of a larger, more inclusive recruitment campaign. These latter companies claim that they actively employ different forms of media to reach different audience demographics, and mobilize their efforts on LinkedIn and Indeed.com as well. Both LinkedIn and Google (GOOGL  ) also offer the option of letting advertisers pitch their ads to only men or only women -- and (unlike Facebook) have recently announced that they will delete all job ads that cater to only one gender.

As a comparatively casual platform, Facebook has the advantage over LinkedIn when it comes to reaching out to the informal economy of hourly workers. Despite having similar work histories, female hourly workers searching for new jobs on Facebook have been frustrated due to finding fewer leads when compared to male hourly workers in the same situation. If they have no male point of comparison, then female job applicants have no way of knowing which ads they aren't seeing. The difference in these two groups' experiences underscores the need for a legal intervention.