Groundfloor: "So its legal....
does that make it right?"
No, it makes it a legal and legitimate usage like it or not.
As pilotbear says, occasionally D&D do notam requests for practice pans for their training purposes.
As for 'invading every flight deck in 150 NM': the practice pan conversation is between the D & D controller and the person practicing: if the D & D controller is happy to accept the call then I'm sorry it offends your little shell-likes: take it up with the CAA if you have a problem.
B