interesting... the counter party in the stock certificate that was posted on the (now deleted) blog is a financial firm. when you look up the address of their UK offices, it's a regus location!
then there is a sister-company to SG in that same certificate.
if you try and delve into their S1 filing and then related auditing firms original share holders (pre IPO), you find yourself in a dazzling web of corporate shenanigans that could make your eyes go square. these guys are pros.