Swearing and colloquialism vary a great deal geographically, in both meaning and intensity, and the internet has the potential to bring about considerable misunderstanding and offence if posters indulge in their customary vulgar forms of speech. Therefore, as somebody has already said, it is a good idea not to use it at all on forums. I think I have dropped the very occasional "bugger" here but on reflection it probably wasn't wise.
At the personal level, in my everyday life, I never use the stronger swear words at all. I think I had such a sickening of them, firstly among university students and then even more so, working on the waterfront. They were interspersed into sentences in what amounted to a random, habituated sprinkling whether offence was intended or not. This is also starting to be the case in television programmes at the moment and is a result of the words no longer being censored. Makers of films have gone berserk with their new freedom and the result is a monotonous torrent of swearing which produces a really infantile effect. Quite frankly, I wish the words would go out of fashion.
Australia and New Zealand are peculiar in that they have the widespread colloquialism "root" for the sex act, usually just used as an everyday noun or verb, and as an pejorative adjective only in the past tense. As far as I know, Europeans and Americans do not use it in that sense. Both households I have lived in have evolved their own internal vocabulary of vulgarities and expletives, used in imaginative combinations on the impulse of the speaker. I have always assumed that other people do much the same but as usual I might be wrong.
So what with global variation, personal habit and familial idiosyncrasies of speech, the potential for complete misunderstanding is really too great to justify swearing on forums.