Hobo and I had a good discussion this weekend about cursing. We both feel like there are two strong forces pushing on our use of 'dirty' words and no clear resolution. Obviously there is pressure to not curse from relatives, officials, etc. but mostly that is something we don't worry about - the real pressures are oppression avoidance and diversity of expression. Note that I am going to writing curse words in this post explicitly so it is NSFW - a little, anyway.
There are a huge number of words that people used to used as insults or curses which are fading in usage due to the fact that they are obviously referring to a marginalized group. That is so gay, this is retarded, Jewing people down, etc. are phrases that clearly perpetuate stigmas against specific groups. Cursing using those words clearly is a problem, particularly when used in a context where some people aren't aware of how the group in question feels and who imagine that this usage justifies discrimination.
The trouble is that I keep extending the prohibited list of curse words further. I don't like using fuck as an insult or curse because quite frankly it is always used in the context of the person being fucked being portrayed as bad / defeated / weak. A word that suggests that being on the receiving end of penetrative sex is bad is definitely a problem in terms of misogyny even if you can get past the general sex negativity of it. In addition anal sex is particularly used to denote being in a truly terrible situation which trashes gay men. Of course gay men aren't the only ones having anal sex (they aren't even having most of the anal sex, not even close) but calling everyone who has anal sex bad isn't an improvement! Lots of folks, straight, gay, or otherwise, enjoy anal sex just as something fun to do and there is no reason it should be stigmatized.
The butt is another favourite topic for swearing. In addition to butt sex being naughty we have a fascination with asses and shit as things to curse about. This, I think, is a little more defensible because feces is actually an unhealthy thing we pretty nearly universally have a taboo about. Nobody in particular is suffering because we think poop is bad. That distaste still bleeds over into problems with rear ends in terms of sex though, but I feel like this is the least problematic area of cursing.
On the other hand we have the problem that our diversity of expression when it comes to cursing is vanishing. Virtually every word aside from 'bad' is problematic for one reason or another and that leaves little room for creative description or explosions of expletives. Striking out portions of language as unacceptable also just rubs me the wrong way - I feel very strongly about being able to use language in whatever way I want. That freedom to use the full breadth of language smashes into my desire to not insult particular groups or denigrate specific behaviours regularly.
I was thinking about trying to mine other languages for curse words I could steal. I don't know if there are words in non English language that mean 'bad' but sound creative and aren't discriminatory, but if there are I want to know about them. Even if my audience doesn't know exactly what I am cursing about they will naturally tend to assume that if I am cursing in another language I am probably really pissed off or disgusted so the general message will get across if nothing else.