Facebook Inc. has in the past been found guilty of abetting race discrimination by how it allowed its users to be targeted with advertising. A new investigation released today revealed that the company also allows advertisers potentially to discriminate by age.

The investigation by The New York Times and ProPublica revealed that numerous companies’ ads for employment would not reach a significant part of the public. The implication is that only young – but not too young – people need apply for certain jobs.

The report found that some of the U.S.’s largest employers, such as Verizon Communications Inc. and Facebook itself, would target job ads to a very specific age category. In one instance, that was 25 to 36 years old, not something often seen in the past in physical format.

Is this OK? According to the Age Discrimination in Employment Act of 1967, it probably isn’t, because showing age bias when hiring is not lawful, according to the act. A Washington employment lawyer said as much in an interview with The Times.

However, although Facebook has admitted to discrimination relating to targeted ads in the past, this time the social media behemoth didn’t back down. In a blog post titled, “This Time, ProPublica, We Disagree,” Facebook said there is no flaw regarding age-based ads.

“Simply showing certain job ads to different age groups on services like Facebook or Google may not in itself be discriminatory,” said Facebook. “Just as it can be OK to run employment ads in magazines and on TV shows targeted at younger or older people.” Facebooked added that if used responsibly, age-based targeting is accepted practice and helps employers find the right kind of people.

Nonetheless, in a time when people 40 and over are struggling in America because of age discrimination and Facebook is becoming a very large employment hub, concerns have been raised. Many of the jobs advertised mentioned in the report could have easily been performed by a person of any working age, yet some of the ads were targeted at only the young.

ProPublica contacted many of those companies involved in the investigation, including Amazon.com Inc. and the New York City Department of Education, and they said they would change their hiring policy. In Amazon’s case, for jobs at its distribution centers, it changed 18-50 to anyone over the age of 18.

In the end, is Facebook to blame or the advertisers? Although the company is protected by the Communications Decency Act regarding what appears in its ads, Facebook is being accused by some of allowing age discrimination — not a good look at a time when it’s facing criticism on a number of fronts.

Image: Alan Levine via Flickr