The obvious (yet politically controversial) solution is to just use one of the many Open face recognition embedding CNNs and then combine with low level appearance descriptor.
Largely the issue with this is that a lot of spammers
don't have photos with faces [...]
One tactic could simply be combining faces(in some offline version of something like: http://www.morphthing.com/, no affiliation).
Another method could be targeted and non-detrimental manipulation of facial constructs. I could imagine using liquefaction filters designed to operate within a perceptually acceptable range for a human while working towards the the goal of gaining enough change to be new in the eye of the facial recognition algorithms.
Still a worthy effort by OkCupid, they'll scrape off the bottom this way.