Note that in addition to ASRS, if you encounter a situation that is unsafe, for whatever reason, you can report it to the FAA via their hotline:
Note that anonymity isn't quite the same as ASRS, but if you "see something, say something". I had a recent "close encounter of the aluminum kind" that I reported. After sorting through with ATC what happened, the best we can figure out is that someone was reporting the wrong altitude and cut through the traffic pattern of the airport. I don't know if they were able to track the other plane down to notify them of their deviation.
Note that anonymity isn't quite the same as ASRS, but if you "see something, say something". I had a recent "close encounter of the aluminum kind" that I reported. After sorting through with ATC what happened, the best we can figure out is that someone was reporting the wrong altitude and cut through the traffic pattern of the airport. I don't know if they were able to track the other plane down to notify them of their deviation.