We're all human. So, give yourself, peers, and instructor the benefit of the doubt first. Sometimes we make mistakes or word things in ways that may offend others. So, if this happens, consider first that the person may not have meant it that way. If it still bothers you, try emailing or messaging the person individually for clarification and explaining why what they wrote offended you first before blasting them publicly on the forums. If you think it's serious, inform your instructor for further action.