SANdyFlyer, i do not see it as vigilantism. Your repeated attempts to go to extremes to belittle other people's thoughts and experiences is unfortunate.
I do not think most anti-seat savers will go out of their way to prove their point. That said, if the last aisle seat is being saved for someone that has not gotten there yet, I will take it.
Finally, I find it interesting that you, the most ardent pro seat saver on this thread, never have to deal with these issues.
I want to thank all the people who took time out to post and repost on this topic. I have learned a few things ( see my summary posts), like I always do on FT.