Chances are you’ve encountered a couple of tech support scams in your days. These people frequently dial random numbers in an attempt to get the person on the end of the phone long enough to trust them with remoting into the device. These kinds of scams are designed to be as vague as possible, and since most people have computers that are at least a couple years old, they tend to experience some kind of sluggishness that makes them believe that something is genuinely wrong. This can turn out to be a grave mistake.
