Was wondering what peoples opinions are with regards to swearing/cursing in films?

Is it needed?
Does it give it that extra edge?
When did swearing/cursing first enter popular films?

I understand with Crime films/programes etc but with comedies im not so sure..

I'm only asking as i was watching a 15 rated film and there was cursing every other word and was thinking if if was needed..

The Mafia Is Not Primarily An Organisation Of Murderers.
First And Foremost,The Mafia Is Made Up Of Thieves.
It Is Driven By Greed And Controlled By Fear.

Between The Law And The Mafia, The Law Is Not The Most To Be Feared

"What if the Mafia were not an organization but a widespread Sicilian attitude of hostility towards the law?"

"Make Love Not War" John Lennon