Most comments simply missed the point. Power analysis attack and power glitch attacks are well-known in cryptography and electronics. The classic technique is

Most comments simply missed the point. Power analysis attack and power glitch attacks are well-known in cryptography and electronics. The classic technique is to monitor the Vcc voltage and current on an oscilloscope and try deducing the internal operation of the chip and extract the secret, or to inject a glitch by on the Vcc rail to induce a fault. A classic side-channel attack, but these attacks required complete physical control over the hardware, and you need to put a dozen of probes on the motherboard in a lab with an elaborate setup, so it was typically not a concern unless it's a crypto key or something (if so, it would be done on a separate security chip with physical defense internally). But this attack showed that, since every CPU and SoC now has builtin dynamic voltage scaling and power management, by using these features, you can use the CPU to launch a power analysis attack against itself, and you don't even need to touch even a single trace on the PCB, the attack can be launched remotely, and all you need is root access! This is frightening. Who knows what is going to be the next.