What should I do if I know a co-worker is being harassed?

A good co-worker will treat sexual harassment to another employee the same as he or she would if the harassment was being perpetrated on him or herself. If the co-worker doesn’t have enough courage to speak to the harasser him or herself, then you should speak to the harasser yourself - again in a firm and serious manner, making certain that the harasser or harassers know that the conduct will not be tolerated. You may also support your co-workers emotionally, and offer to help him or her file a sexual harassment claim with your company and, failing that, with the EEOC.