Easy for me (basically none). I don't carry a phone while fishing. If I hear (before going out) that there are fish in a certain area, I will consider fishing the area, but only if it is an area that does not draw a crowd. I pass general fishing information to an extremely limited amount of friends (can count on less than one hand).
I kinda look down on cell phone use while fishing in terms of notifying others. I figure if I am out there and into fish and someone else in the area starts getting into fish and calls others, he is basically screwing me.