Is there a difference?

I'm not a lawyer, but my understanding is that inclusionary targeting is legal whereas exclusionary targeting is not, and exclusionary targeting is what's happening. Inclusionary targeting uses logic of the form, "This user corresponds to subgroup A; load content specialized for subgroup A." Exclusionary targeting is of the form, "This user corresponds to subgroup A; do not load any content for this user."

If you'd like to target a specific demographic you can do so using either inclusionary or exclusionary targeting. Only one of those systems also allows you to explicitly exclude one or more groups rather than just target a subset of groups. Your example seems to be a very charitable interpretation of how exclusionary targeting could be used. There's (probably) nothing wrong with it if it's used that way. But you could just as easily use the system you described to prevent a variety of protected demographics from being able to see the advertisement whatsoever.

It’s not even that deep or complicated. You can target however you want to except when it comes to housing. They can’t claim ignorance. When I use to run ads as a landlord in the paper, the paper had specific guidelines in their real estate section and would deny any ad that broke the guideline.

https://www.ajc.com/visitor_agreement_mobile_old/

Equal Housing Opportunity. Any real estate advertising on this website is subject to the Fair Housing Act, which makes it illegal to advertise "any preference limitation or discrimination based on race, color, religion, sex, handicap, familial status or national origin, or an intention to make any such preference, limitation or discrimination." Georgia state law also forbids discrimination based on these factors, except that it forbids discrimination based on "disability" rather than "handicap." Familial status includes children under the age of 18 living with parents or legal custodians; pregnant women and people securing custody of children under 18. To complain of discrimination call the U.S. Department of Housing and Urban Development at 800-669-9777.

Anyone who's ever even looked for a roommate on Craigslist has seen all this information, too. I'm actually kind of flabbergasted that Craigslist handles it correctly and Facebook does not, just given how much more competent Facebook seems based on contrasting the look of the two sites.

It’s slightly different with roommates. You can’t discriminate in advertising when it comes to roommate but you can discriminate when it comes to housing according to one ruling.

https://www.sharinghousing.com/what-the-fair-housing-act-mea...

Craigslist says something different.

https://www.craigslist.org/about/FHA#roommates

Under federal Fair Housing law, the prohibition on discriminatory advertisements applies to all situations except the following:

Shared Housing Exemption -- If you are advertising a shared housing unit, in which tenants will be sharing a bathroom, kitchen, or other common area, you may express a preference based upon sex only.

Private Club and Religious Exemptions -- A religious community or private club whose membership is not restricted based upon race, color, or national origin may restrict tenancy only to its members in a property that it owns, and may advertise to that effect.

Housing for Older Persons Exemption -- As discussed below, certain complexes for elderly persons are exempt from prohibitions on familial status discrimination, including the prohibitions on discriminatory advertising.

Craigslist says the same thing

>Decision-making: Although the prohibition on discriminatory advertising applies to roommate and shared housing situations, federal Fair Housing laws do not cover the basis of decisions made by landowners who own less than four units, and live in one of the units. This means that in a situation in which a landlord owns less than four rental units, and lives in one of the units, it is legal for the owner to discriminate in the selection process based on the aforementioned categories, but it is illegal for that owner to advertise or otherwise make a statement expressing that discriminatory preference.

> will be sharing a bathroom, kitchen, or other common area, you may express a preference based upon sex only.

I wonder if someone who has a particular dietary restriction (kosher, halal, gluten free, vegan, etc.) can express a preference for a like minded person.

As long as it’s not a protected class. For instance, I was once a hiring manager and everyone I was talking to was shocked when I said I would rather hire someone older and more stable. They thought I was opening them up to a lawsuit. Being under 40 is not a protected class. Being over 40 is.

I also told the recruiter that I wasn’t going to hire a guy because he smelled like cigarette smoke, I would be working closely with him and it bothered my asthma. Cigarette smoking is not protected in some states - including mine.

My understanding is that the "shared housing" clause is still only applying to landlords, not individuals seeking a roommate.

So if you're the Catholic Church running a women's boarding house on the upper east side of Manhattan, you are allowed to advertise to (and rent to) only women, but you can't restrict it further to only Catholic women.

OK, true, but I've also rented out entire units on Craigslist before too, so I've seen the full disclaimer regardless.

Speaking of which, the Roomi app might potentially be doing illegal things in turning housing search into a social network.

You wrote it backwards. Discriminating on roommates is legal.

The first cite said you couldn’t discriminate in advertising but you could discriminate in selection. Craigslist said something different.