reasons why terrorists won't attack chennai or kolkata

1. there are various but lets start with this.... both these cities are extremely crowded... there is perpetual traffic jam... even if the terrorist did want to bomb a certain place at a certain time, it would be impossible to get there on time because of the incessant traffic jam. and the bomb might just blast off making the terrorist immortal and register himself on the martyr list.
2. both the cities are high on humidity levels, and when i say high i mean really high i mean really really HIGH... HIGH HIGH. now that you have got the point, the bombs just wont blast, they will try to blast, but end up just fizzing around and making people think that the bomb is some kinda snake.... they will be terrorised neverthless. 
3. both the cities (with due respect, to atleast kolkata) stink. there is a perpetual over flow of  nali water. i'm sure the terrorists dont want to wade through 3 feet water before they get round to terrorising people... and they will stink.... of the nalis. and the fact that they have been apparently trained in dry areas, that is not a very good place to be in. 
4. there is only so much of maach bhaja  and dosa sambhar a person can eat. since the dry fruit stock is no longer going to remain dry (see pt. 2 for reason) they have to eat local food to survive. and that is possible only if the terrorist hire the local people who are used to such food. and that is difficult... all chennai people and the kolkata people are very sentimental about their cities.
5. people in these cities are loud. they can scream at the top of their voices, out doing a loudest microphone by a large margin, and specially the women, and these women are trained spies of their own accord. and if anyone gets a sniff of the terrorists trying to terrorise, they will scream and alert everyone within the radius of 3 miles before the terrorists can silence them. and the people will beat them up relentlessly, they would not wait for the police to arrive. since they know that the police or the authorities will be stuck in the traffic snarls mentioned in pt. 1. 
6. these cities are both terrorised already by jayalalitha and mamta banerjee respectively, y confront them?
7. the terrorists are human too, they know that kolkatans and chennaiites already go through a lot in a day. hanging in a local train in the high humidity & stink (pt 2 & 3 for ref.) having to suffer the rain all year. and then the potholes... and ofcourse the two mighty women (pt. 6), im sure they dont want more woes on these poor people...

jokes apart, its a good thing such a thing hasnt happened in my beloved kolkata, and other's beloved chennai. and i wish they remain the same. happy terrorising to these two cities.