Can You Access a Computer That's Not in Sleep Mode?

"I feel like I'm definitely on some type of government watch list now," the hacker writes. "Please again, computer security experts out there, let us know, can you access a computer that's not in sleep mode?" A few MIT students were able to prove that Wi-Fi routers can be used to remotely detect how many people are inside of a room at any given time. There was no mention of a noise being emitted from the routers, let alone a noise that could elicit a response such as this one.