Correction and update: An earlier version of this column was based on a mischaracterization of the Bumble app as being for women only when in fact the app is for both women and men; its new feature allows users to filter for just women. This update reflects actual attributes of the app and its potential uses. The earlier version also misstated the name of Bumble's social networking site, Bumble Bizz, and misspelled Bumble CEO and founder Whitney Wolfe Herd's name. The column has additionally been updated to include a response from Bumble.

Imagine a company sending out a press release to announce that they have a new networking tool that only allows men.

Bumble has just done that--except it allows users to filter for just women with its new Women in Bizz feature. Is there a difference? Nope. When we want to check our biases we can do a simple test created by Kristen Pressner, in her viral TedX talk: Flip it to test it.

Regarding Bumble's reasoning behind the new tool, CNBC reports that CEO Whitney Wolfe Herd said:

"Representation is critically important for women, especially in traditionally male-dominated industries. We're helping women connect with other women to show them what's possible and give them resources as they build their careers."

That sounds warm and fuzzy, and helpful to women, but you need to be really careful with networking apps. Why? Because this makes it easy for recruiters to exclude men from their searches.

"I'm struggling to find a way this isn't enabling sex discrimination," said Employment Attorney Jon Hyman, regarding Bumble Bizz's women-only filter. "If an ad says '______ only need apply,' we'd all be pitchfork bound to the company's HQ. How is this any different? If you screen out one protected class in favor of another, it's unlawful discrimination. End of story."

To be sure, Bumble Bizz is not a recruitment app, nor does it support its use as such. It is specifically a networking and mentoring platform, says a Bumble representative. "As a woman-first social networking community--and knowing that workplace gender inequality is still alive and well--we wanted to give our women users the added layer of customization within Bumble Bizz that they've been asking for."

Even so, in the hands of misguided recruiters bias may take root. And that's plainly illegal, except in rare cases in which gender is a bona fide occupational qualification--like an actress for a particular role.

Title VII prohibits discrimination on the basis of sex in the workplace. It doesn't say "you can favor women over men."  While you and I both have freedom of association and if I wish to only accept LinkedIn invitations from other women, I'm free to do that. (I don't.) But, if I'm working as a recruiter, that can become quite a problem, as I'm no longer acting as an individual, but as a representative of my company (or my client).

I'm rather amazed that neither Fortune nor CNBC, which wrote about the new women-only networking tool, didn't question the illegal discrimination aspect. CNBC went so far as to write:

"Bumble Bizz is used by recruiters or hiring managers to find new talent, so limiting the potential pool could help women compete for jobs in male-dominated industries."

Recruiters should be looking for the best candidate, regardless of gender. It's the only way to be compliant with federal law.