I'm not sure...the author's projects page (http://lav.io/) is full of politically satirical/subversive work, such as "CSPAN-5: autogenerated supercuts of CSPAN videos" and "Big Data Pawn Shop: leaked NSA documents printed on merchandise" and my favorite, "Yelp Prison Review Faxbot"...so it wasn't likely something he investigated.
OTOH I've been fascinated that these are even endorsement categories and of all the subcategories beneath them...not shocked...just surprised because the endorsement tags I always focus on on LinkedIn are things like "Ruby on Rails" or "Front-end development"
I could be mistaken, but I was under the impression that the endorsement categories were not a whitelisted set and that you could endorse someone for basically anything.
OTOH I've been fascinated that these are even endorsement categories and of all the subcategories beneath them...not shocked...just surprised because the endorsement tags I always focus on on LinkedIn are things like "Ruby on Rails" or "Front-end development"