Throttle Cut for Another User Logging Into Your Account

Hey, I was flying a long haul from Madrid to Atlanta. I was flying on the expert server. I was approaching the state of Georgia when suddenly, I got a message saying “another user has logged into your account. As a result, your throttle will be cut. Contact support if you have any questions”. Obviously, my engines were cut and I crashed. Why did this happen, and does this mean that my account was hacked?

We experienced server issues earlier today which caused what you are describiing.