Anyway, to address the two main points I would like to clarify for people:
1. The basic premise is that murder at some point in the future is too difficult to get away with, so future mobsters send bodies back to be disposed of. You must accept that premise as the background and move forward from there. Critiquing the movie on that point is like critiquing the movie for having time travel at all saying that "time travel inherently makes no sense." Slightly more valid question is why they don't send their victims into the distant past, but again, the premise is the premise; I don't think the details of the "tagging", etc. need to be explored when the focus of the movie is on identity, selfishness, violence, impact on children, etc.
Well, at least time travel leads to interesting "what if" questions. I don't find the tagging technology interesting, in addition to it not making much sense. I think it's a pretty valid criticism for a movie being championed as "brainy sci-fi."
The entire concept of the Loopers just seems awfully silly and contrived, with mobsters using time travel technology and setting up this entire, complicated system.... just to off people?!? (Really? Because they don't have incinerators in the future or something??)
Supposedly, they have 100% perfect tracking and biomonitering implants in the future. If you kill someone the police will know exactly when they died and who was there with them. That means that the identity of the killer will be pretty obvious.
Sending them back in time means that they vanish from the tracking system, but there is no death signal.
Ok, so they just disappear. Let's think about this. If this system is 100% perfect and never loses tracking, then the signal going dark would be equivalent to a death signal. If not you could exploit that flaw in the signaling system to kill someone and destroy the body/tagging without using time travel (aka the most illegal thing of all).
Whoa, people keep disappearing from the system right after these 3 mobsters abduct them and take them to abandoned buildings!!?!? Someone call Matlock, this it too perplexing!