Whilst its clearly good news the matter was a hoax, unless and until the perpetrators of such things are forced to pay the full costs of the event there is little reason to believe they will stop.
The RAF jets alone will be over £100,000 worth of resources, and that's before the airline and passengers get involved. These people should be breaking rocks until the bill is paid in full.
But hey ho I'm sure its against their human rights or whatever...