Calciphylaxis. Calciphylaxis is a condition characterised by necrosis (cellular death) of the skin and fatty tissue. It is seen mainly in patients with end stage kidney disease. It is also sometimes called calcific uraemic arteriolopathy.
Besides a data link, USB provides 5 +/- 0.25 volts to power an otherwise unpowered device or charge a battery in a self powered device. A USB controller or hub is required to power one unit load (100 mA, a low power load). It can optionally power up to 5 unit loads (500 mA, a high power load).
you said..: Power almost anything off USB Port, well powering my house didnt work. just for future reference. This is wrong. If your circuit requires 3V nominal and a maximum of 4V then you could not use a 5V USB port to power your circuit.. You risk destroying your device. If your circuit requires 7V you could still use 5V to power the circuit.