AFAIK the litter line doesn't need 3 reports. One report with a witness' signature, time, date, location etc etc and they'll issue a fine...If the alleged offender chooses to contest it, the accuser must testify in court or the fine is dropped.
They basically issue the fine in the hope that the person will think 'ah well its only $50' and pay it rather than go through the hassle of contesting it. But more often than not if you contest it, it'll be dropped.
My Outdoor ed teacher in year 11-12 was a major enviro freak and encouraged us all to dob in litterers, and even supplied us with the forms to do it (Although he shrunk them from their usual A4 size to fit 2 per page )