I usually don’t swear, but rather ignore people quickly and/or make my disregard for them or what they say very clear in a ‘civilised’ tone; furthermore I tend to avoid getting emotional.
That, of course, doesn’t mean I want others not to swear, not everyone has to behave exactly like me for me to be happy :)
If they violated a core principle of yours? Sure thing! :)
Talking to parents and talking to someone over email are totally different things. In email, you need a way to express emotion and this is Linus' way