From The Soufan Group's conclusion on Berlin:
Among the many counterterrorism challenges European authorities face, they will now face even greater pressure to secure venues that were not designed to be secure, against a weapon that was not designed to be a weapon.
Link:http://soufangroup.com/tsg-intelbrie...uck-in-berlin/

This point has been made, when it is quieter by those who advise on preventing attacks, that the enemy can easily adapt and bypass such static defences - however sophisticated (see BBC story with much "spin"). When vehicles were stopped from parking directly outside airport terminals here it was pointed out transferring an IED to a luggage trolley(s) would be just as effective - sadly as proved by Brussels airport.

Yesterday's BBC story:http://www.bbc.co.uk/news/uk-36806691

A better BBC report today, by a different author:http://www.bbc.co.uk/news/world-europe-38377884