EJS: Too Much Lard In Plane Seats

EJS: Just got back from Denver yesterday and I have a question: When is it OK to say something and what do you say, to the gigantic person sitting in the seat next to you on the plane when they completely infinge on what little space you already have? This is the third trip in a row that this has happened. Man, people are getting way too big. I know there is a difference between a “big” person and a “fat” person but, there sure are a lot of big fat people traveling these days and they seem to have no regard for their neighbors.

Question: What should you do when you encounter a situation like the one EJS faced today?