Anyone you see speedhacking or flyhacking is almost certainly just a visual error from blink or a flightpath or any number of other reasons. It's a fairly common bug on private servers, and even popped up on retail vanilla because of how the client and server interact regarding latency.
The item that lets you avoid combat is a problem, but looting chests without needing to kill things is hardly a serious threat to the economy, just a minor unfair advantage to people who abuse it. They should be suspended or banned, of course, but come on.