From Flintstone:
...someone needs to tell them otherwise the frequency may not be clear...
Maybe that someone would be ATC, realising that an actual emergency is going on, but it sure as heck isn't you - you have no authority at all to be advising other people! Or do you hand out home made parkingtickets in your street, too? It is your call that just might be blocking someone calling for help.
If someone crosses the street on a red light, do you run after him to tell him that he just walked on red?
Nic