Even though I think paranoia will only add to our problems with security, I do think that prudent choices should be made when attempting to protect the public. Certainly times of celebration bring larger crowds out into the streets and I think tighter security is warranted to make sure that areas are as protected as they can be from any threats.
It seems that terrorists are targeting gatherings of people that are associated with times of celebration. Accordingly, security should be tighter and more visible during those celebrations. Terrorists are drawn to soft targets and the bigger the presence of security the less a terrorist will be drawn to attacking a particular gathering.
Yes, security should be tighter during times of celebration. Not only are crowds larger, but due to increased drinking and general revelry, individuals are not as attentive to suspicious activity going on around them. Also, terrorists may be able to hide in plain sight if costumes are involved or crowds are distracted by a parade or fireworks.
Yes, security should be tighter during times of celebration. Terrorists and other criminals do not want people to be happy or celebrate, so these times are significantly more risky for crimes. Also, any time there is a crowd, there is a better chance of crimes being committed, either by participants or those who see an ideal target.