I believe just installing cameras will not help.. Lets assume they install cameras everywhere in major and minor points. Who will keep looking at it 24/7?.. Now again lets assume, security guys are hired to look at it on shift basis 24/7 to monitor them. Don't you think terrorists may blast first that spot where it is being monitored and then go to nest point immediately..
Always believe in this theory "YOUR ENEMY IS FAR MORE CLEVER THAN YOU ACTUALLY THINK HE IS!" The IB and CBIs must devise a fool proof plan to tackle this kind of sensitive issues..