How can I report someone in the us illegally

I really don't think there are many who care unless the II is a criminal, etc... but if it's a concern to you, you should contact the INS (http://www.uscis.gov/) and Homeland Security (http://www.whitehouse.gov/homeland/).

Why do u need to report this person ? Have they harmed u or made threats to the us ? U need to stop being so selfish .Just think of all the tax payers money it takes to deport these people .There are hungry people in this country that could us that money .