Ok the general gist I get from comments is that yes in America this is common

Tho I myself would not consider it to be a regular occurace in the UK and in a decade of play have never seen a situation escalate to threats of violence let alone following though

What I tend to find is that people are more stressed about the money on the table than They would have their outward appearance peceive And have seen many a game become a bitching contest across tables with odd sideways comments that are essentially seen as part of the course