Maybe not a fine, but ... I don't know, some people feel the need to yell and swear really loudly, especially when they're having a screaming match with someone walking away from them. That's not really necessary. Also, on the bus.
Other than that, a fine seems pretty excessive, especially if it's a situation where you're having a regular conversation with someone, and say a cop happens to walk by and hear you swear. I'd be pretty pissed, and my displeasure with the situation would probably end up with more fines. $240?? That worse than a speeding ticket, and you're not going to kill anyone by swearing.