Quote: Ferocious Aardvark "It's even worse than that. There only ever was a Nice incident because the lunatic managed to perpetrate the act. But had he been barred from driving into the area, then nobody would ever know or even suspect that such an insignificant "stop" had prevented a massacre.'"
It would have been nigh on impossible to blockade every French Town/City centre for the Bastille Day celebrations and if, a "lock down" is required before any "mass" gathering of people, there are all sorts of issues with staging these type of events. Even the different types of "protest" march that we regularly see in England, would become difficult to stage.
Of course, any type of gathering can become a target, if somebody or organisation wishes to target civilians (The Boston Marathon being a prime example).
Ultimately and ironically, this ends up being part of the cost of freedom.