The last couple of flights I was on the E+ was about 50% capacity and the exit rows were about 25%. The FA made the announcement that people are free to change seats except from the back to the E+ seat; added that E+ seats costs $$. (Interestingly, they did not mention exit rows which are E++ in my opinion. ) That did not stop people from moving to the E+ seat without asking. I have no problems with people moving to E+. However, moving to the exit rows are a different situation. One is money or theft, the other is safety. While most people don't take the responsibility of seating in the exit rows seriously, I do. As many time as I have the safety briefing cards at the exit row, I read it each time I sit there. count me as a nerd.