Just out of respect, you should not say obscene words or do obscene things in front of others that may not want to see or hear them, especially children (weather they want to, or not ).

Should it be against the law to use them in public… I don’t know.

Using an obscenity out of anger could be just like throwing a punch and elicit a “punch” in response. Accidentally saying one while slipping in a puddle in front of a playground full of kids is still using one but not with malice, does that make it different? Don’t know.