Bottom line: If you think you’re data is safe, it isn’t. Even if you use a computer that’s not connected to a network or the internet, hackers can access your data via your power lines.
So, if your computer is plugged in, your data isn’t safe.
Hackers can access computer data via power lines
In the past, using an “air gap” was considered a foolproof way to keep a computer’s data secure. Now, we know that hackers can access your data through your electric wires.
Read more about this at Hacker News.
Quick Tip: If you want to secure data stored on your computer, only turn on your computer when it’s using battery power. Also, never, EVER assume that any of your data is safe.