Just an fyi...zipper merging reduces lengths of backed up traffic and wait times. Unfortunately most people aren't aware. If you are blocking the other lane, it's you who is being inconsiderate to everyone (I use to do it btw).
As for fishing...Some people just aren't aware. Although last year I had 3 people in a small boat motor past me and my dad as we worked a bank so they could beat us to a good pocket. They only spent a few minutes there and left and we proceeded to catch a couple. Getting mad at someone fishing your hole is never as bad as you make it out to be unless they are using dynamite.