grip it and rip it, I can't help but laugh at people who put a float on their line even though their line to their leader is 10 feet and their leader is another 3 feet long, so the wight catches the bottom and gives them an "excuse" to rip their hook through the water in attempt to catch a fish. i have seen in all over the river, i usually ignore it, because honestly, i could say something, but a few words isn't going to get though such thick skulls and change a person's method of fishing unless he is getting a visit from a CO or DFO and receiving a ticket.
I have seen people get into fist fights and thrown in rivers for beaking and arguing over simple things, I think it's highly unethical, but people are going to do what they want regardless, and a lot of the time it's the people who are trying to be ethical and help people that get screwed in the long run, people just want fish, and nothing is going to change the metality of having to catch a fish, because they go to the river to catch something, not stand around a body of water and throw hooks at fish and hope they bite. its pathetic but nothing is going to stop them.
I Stopped bottom bouncing 3 years ago, and now the only time i fish the fraser river is to fly fish for pinks or fish for sturgeon.
best thing to do is give them some advice, maybe if they honestly don't know the proper methods to fishing effectively give them a float or two if they don't have any, and teach them how to set everything up properly. But if they are ignorant and don't want to listen try to ignore them, and if need be move to a different location.