Could really use a little context as to whom you wish to have a discussion. From an HR standpoint this is nothing more than a lawsuit waiting to happen and for obvious reasons. Unless you can find a very creative, if not legitimate reason to use such a service I would avoid the entanglement.
If this is one of those "friend of a friend" or "asking for a friend - I'd still approach this with kid gloves. Maybe latex if its latex Tuesday or such.
Strictly from a technical perspective you need to know the false positives rate before officially naming someone. Again, this is a quagmire of yuckiness just waiting to happen.
As a service as a whole, I am utterly against anything of this kind, whether it's checking what someone did in the past for the (imo) safety of guys who's gf's may have been actresses (which may in some circles count as a bonus) or checking whether someone is suitable for work by trying to find their social media behind their backs.
I will accept that there are certain situations in which facial recognition tools can be put to good use, but it should be done in accordance with the legal rights to do so, and for a very good reason.
Not sure about the US, but here it is considered stalking, which is sue-able under law.