On another thread (concerning possible Manpad threats) somebody mentioned the advantages of encouraging spotters to be aware of security risks and making arrangements for them to contact security ops easily. I think this bears out the point, given that they were apparently able to video the incident. Why not put up a few motorway type emergency phones around the perimeter/publicise a direct phone no. for LHR Security? The downside is that it would attract !!!!!!!! calls, but that's trivial.