I can see it now;

Start of PUG:
Guy one: So, we all upvote each other at the end of the dungeon?
Everyone else: Yup

Or if they limit it to one upvote per party;

Start of PUG:
Guy1: So I'll upvote 2, 2 upvotes 3, 3 upvotes 4, 4 upvotes me.
Everyone: Agreed


This is just begging to be abused. Please don't follow through with it!