well, for those wondering whether it is safe or not, i purchased my antminer on a saturday... sent an email and received no response (no email from purchase nor when its shipped nothing), however, monday was shipped, and by wednesday/thursday was at my house.
it's been working for the past 2hr~ at steady 178GH/s (no overclock) w a 750corsaircm... all good, recommended...
Purchased from whom? Bitmain? They are kinda slow with responding to e-mail but pretty good at getting merchandise out the door. But I am curios in case you got that from someone else.