Is it open for public/commercial use freely? Or will Getty images / ect start hunting for using bitcoin logos
If you're referring to the original, posted by HeRetiK, you are free to use it without fear for copyright trolls.
But once you start modifying it (if I remember correctly the terms where modify,change and expand) you can claim copyright on it.
Istock has a lot of them protected by copyright.
So stick with the original.