This is a somewhat random note on the subject, but after reading one of the threads yesterday on Stripe, I found myself reading through their list of prohibited businesses/services (it's an interesting read if you're curious about high-fraud/sketchy business models).
And sure enough:
54) human hair, fake hair or hair-extensions
which says a lot about the industry.
(Note in looking this up just now, I found its only in the UK prohibited businesses, not the US list, which is also somewhat interesting)