Rather than assuming everyone else is untrustworthy, my approach is different. I just run my simple greed on everything (but main spec upgrades) regardless of what others are doing. I don't even wait to see what the others do. Loot comes up, not an upgrade, "Greed".
What's the worst that can happen? I lose a loot to a ninja? Heck, I've even been able to gear up several of my companions in Columi gear gotten from greed rolls.
What's the result my approach? NO DRAMA!
Have you made any friends in these pugs you have been Needing in? You do understand these pugs are on your team. You should be fighting the other guys and gals, not your team.
I have meet and stayed in contact few from pugs in group finder, because I treat everyone I group with the same. I see no difference between a guild run and a pug run in my behavior. It is a group effort and needing just because you believe you are entitled defeats the entire purpose of playing a MMO.... If you want everything as if you are playing alone, go play a single player game.
Hmm, my personal practice was really not up for discussion - but just to humor you folks:
I practically pass on every single loot in every FP or OPS. I can literally count the loot items I've gotten since December on one hand. All my toons are fully or partially geared through PVP, dailies, bh comms or GTN - same goes for the companions I use. *I*, personally, could care less what loot rules are followed or not.
My idea was simply in response to the numerous complaints (here and in-game) about what was perceived as "ninja looting" in groupfinder teams and the expected increase of such complaints with the imment introduction of F2P.
Obviously, I a) failed to clarify that sufficiently and b) am now convinced that people rather complain than change the system. Kinda like politics - we vote for the same crappy parties every time and then b*tch about the results.