That’s not true either. Byte can be both powers of 10 and powers of 2. When talking about storage devices like hard drives etc. we usually refer to them in powers of 10, but OS’s usually do it in powers of 2. That’s why your hard drive looks smaller than advertised.
Bits are used for flash memory as individual chips. Assembled devices such as RAM and memory cards are advertised in bytes. I’m imagining that the same goes for hard drive platters and possibly disc media as well.
Relaying sensitive information over your own wires are a lot more secure then a privately owned service from a foreign country. It’s just a lot more cumbersome.