If in doubt, don't confront!!!!!!!!!!
I would politely inform that they are fishing illegally. But I would NEVER confront ANYONE. Call the poachers hotline during WEEKDAY fishing ONLY!!! They don't answer on the weekends. You must call the Washington State Patrol on the weekends, they inform the officers from there. I know first hand, have tried calling the hotline on sat/sun, get refered to call the WSP, unless they changed it since last October.
Onto confronting. I've seen this FIRST HAND. This was mostly PRE cell phone, but have seen even within last couple years. I have actually seen guns pulled. Have made reports, and have called via my cell (if I had coverage). Problem with someone pulling a gun, a cellphone isn't going to help if they pull the trigger. Normally a person who pulls a gun for that stupid of a reason, has more of a chance of squeezing that trigger to avoid a ticket/jail (I know, stupid, but guys do it). Most guys who knowingly poach, sometimes will pack. I simply do as I say above. Politely tell them that they are in the wrong. Then, if I get a shrug or a "F O", I make a phone call. When I say polite, I mean "Hey, isn't this river closed to fishing/gear fishing/etc". If I get a "NO, or a I don't think so" I inform them. Then, what they do from there dictates my move. Ignorance of the law isn't an excuse, I understand that, but I prefer to educate someone who's not in the know then to punish. Would rather have them have a respect for fellow fisherman/women then think we're snobs or arses. I know I've informed one gentleman with his son on the Satsop a few years ago. Was fishing out of season (I was doing a scout float to check out the river to see if it had changed, no gear on board). Explained things to him, and have seen him many a times over the years now. He has given me a thanks, and I've even helped him with appropriate gear as well. Watched him go from unprepared, to well outfitted. I guess I prefer to try and reform if possible (you can tell by body gestures and facial expressions if they are doing it on purpose or not). Heck, you may even take a guy and make a fishing buddy that way. Maybe even be a mentor to someone. Can happen.