Originally Posted by flyerCO

In reference to earlier post. As you don't have exclusive control over the seat (unlike a rented house where you have exclusive control of the house) you have no right under law to have the poacher removed for trespassing. Only the airline has the right to demand they be removed from plane. Thus why performing a citizens arrest will only likely result in you being the one charged. Again, unlike a police officer, you don't have immunity if the person sues you for unlawful detainment. You can also be arrested for false imprisonment/unlawful detainment.