I tried to subscribe to this, only to have their billing system tell me my address is nonexistent. Received a support e-mail from someone named Rajish Rupaldi who asked for my full (unredacted) credit card number and my SSN so he could 'urgently process manual transaction.' I told him just to forget about it. There's definitely some shenanigans happening in their billing department which my financial info doesn't need to be a part of.
I have NEVER heard of a SSN being asked for to complete a purchase of a product before- definitely something is going on.