i use profanities all the time..
i scold like mad when im driving.. especially when people do not signal and just cut my lane.. usually i scold a word or two and take revenge by overtaking and slow down by alot..
recently, i just got a new rear bodykit because some punk driving a fast car decided to cut my lane for no reason (well.. i actually believe that it is my ride that attracts this kind of attention)... so.. i just overtook him and slow down (i didnt jam brake)

anyawy, i use profanities within siblings and friends.. not to the adults at home..
however, in future, i wouldnt mind my son/daughter using profanities.. to describe or to vent anger.. but never to use it on me/elders.. or i probably give them a tight slap..