I'm sorry, but just MUTE players that swear if you don't want to hear it. Swearing will not result in a ban, it is not against the terms of use to swear over Xbox Live, so don't waste your time filings complaints just for swearing. That is not the same as verbal abuse, which should be reported.
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If you see expletives or abusive language in bio's, that can lead to a ban, and should be reported.
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I swear like crazy, I mostly play with adults who swear as part of our daily language. When playing with children, I will try to modify my language, but it is up to the child's parents to protect them and set up the parental controls, or turn the voice volume down to zero on the console, so the child playing won't hear the other gamers.
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If you don't want to let your child hear swear words, don't let them play on Xbox Live with in game voice turned up.