Report Illegals is an online service that will report illegal aliens and illegal alien employers in the United States to the appropriate law enforcement authorities for you by acting as an intermediary. All you have to do is go to their website (linked to above), fill out a form, and pay a processing fee of $10.
After receiving payment reports are reviewed and if determined to be valid are reported to American law enforcement authorities such as Immigration and Customs Enforcement (ICE) as well as Customs and Border Protection (CBP). They may also file reports with local law enforcement agencies.
People submitting reports to Report Illegals have the option of remaining anonymous or providing their contact information just in case Report Illegals has any questions for them.