|Do you know where your variables are?|
There is a good solution, make sensitive people type in their own personal list of bad words. If enough sites make them do that, after a while laziness will crush any sense of "bad-word-ness" that exists in society.
On a more serious note, you likely wanted "\b" rather than "\s" at the beginning and no \s at the end either. Your way used on "go f**k yourself you f**ker" yields "go[censored]yourself you f**ker", which isn't likely to be the result you want.
Worse, people like me will delight in finding new variations that get by your current filters. Like pr0n and fsck and "fock cucker" or even "Kcuf!". L33t speak became a real benefit to society when it helped AOLers get around useless filters.
Oh yeah, I won't even get into the problem of regex dealing with the difference between embedded sequences vs. prefixes and suffixes and grammatical declension. "Skys[censored]per".
Filtering is a Tar-Baby. It looks easy to beat-up but every attack you make just gets you in deeper. And, now that I've made that analogy, I might start calling you Brer-lemming just to be mean. =)
Finally; If you want to see cussing, start censoring people.