Define security pupose..., it has a lot to do with how much you are valuing something - a session id is a throwaway value that is used along with other controls. A session id alone is not of much use except in gaming and novelty. It may make the application appear more sophisticated, but we are talking one inch off the floor in a room with an 8 foot ceiling.
"The differential equations that describe dynamic interactions of power generators are similar to that of the gravitational interplay among celestial bodies, which is chaotic in nature."
Mo-om! You're embarassing me! Can you just read a tiny ad like a normal person?