I agree with paulfree14
's analysis that sex workers / sex worker rights activists are a natural fit for Hubzilla.
Other groups who are likely to be receptive to the virtues of Hubzilla:
* People upset with Google/Facebook selling their information to advertisers, Federal government.
* Darknet market users. Reddit banned a number of drug related sub-reddits recently including some as innocuous as /r/beertrading.
* Gun enthusiasts. Youtube has demonetized a bunch of gun video producers and banned several others. Same for Reddit, Google Ads, and Facebook.
* Cryptocurrency enthusiasts. They understand and value the benefits of decentralization. And they're currently under fire--Facebook, and Google have banned/will soon ban all cryptocurrency related ads. Mailchimp will no longer allow cryptocurrencies to be marketed via their service.
* Indepence/rebel movements, such as the Catalonian independence movement. During the runup to the secession vote, the Spanish government heavily censored the internet in the region.
* The unhosted / zeronet / beaker browser enthusiasts.
* Wikileaks and other whistleblower organizations.
* People living under heavy censorship regimes (North Korea, China, Cuba, Zimbabwe)
* Survivalists / preppers.
* Communists, Black Lives Matters / Antifa groups.