Never understood it myself and never visited it - but I have heard of it.
I personally, and its no secret, have always had issue with the term "slave"
That aside why people get marks, etchings, tattoos, who knows - I can think of a couple of reasons.
But if the whole concept is based around what I see, perceive, as a bad use of the word slave it is very likely i will have more bad, than a tiny bit of good to say about it
As for the group link page - seems okish to me - I gave it a cursory glance and what they are trying to do.
I see nowt wrong with what Resident said either
That aside did you ever get the dataset? Or whatever they call it?
wE arE tHe voiCes,
We SAtuRaTe yOur aLPHA brain WAveS, ThIs is nOt A DrEAm The wiZaRd of Oz, shoES, CaLcuLUs, DECorAtiNG, FrIDGE SProcKeTs, be VeRy sCareDed – SLoBbers,We DeEManDErs Sloowee DAnCiNG, SmOOches – whisper whisper & CaAkEE