Liz, I don't know whatever happened to good manners, whether someone is a christian or not. Maybe it's just where I came from, but when I was a kid, seemed like men might do this from time to time, but usually never in front of a lady or children. And, even then, there were certain things that were off limits, such as the "F" bomb or taking the Lord's name in vain. You didn't hear it on TV, radio, etc. either. Seems like when it began to show up on TV and other media, it somehow became acceptable.
I've always worked in a man's world and I have to admit that there were a couple of years that I was away from the Lord and I was around it so much that I became pretty pottymouthed myself. When I came back to the Lord and being a parent, this wasn't something I wanted in my life so I prayed that God would help me stop. One day I was really upset about something and opened my mouth, expecting something pretty ugly to come out..and NOTHING came out. At that second I realized that God had answered my prayer and started laughing like a crazy person. God has an awesome sense of humor.
As to what to do about it, an old friend of my dad's showed me. He was a Nazarene Pastor and he was helping my dad do some work on the house. My dad wasn't a christian, but, of course, his friend had been witnessing to him. Something happened and my dad took the Lord's name in vain. His friend just stopped and stared at him. My dad was embarrassed and apologized to his friend, but his friend just looked him right in the eye, smiled and told him that there was Someone else he needed to apologize to. My dad became a christian a few months later and stopped completely.
Pray for the people doing this around you.