Wait 'Til I Get Going

When people talk about the ambiguous "they," is it a single group of people being referred to every time or are there different groups of "they"? Do the people that are being referred to refer to themselves as "they" or do they call themselves "we"? Perhaps to avoid confusion when referring to themselves they have a special term that only "they" know. If this is the case wouldn't "they" be that and not "they"? To be completely vague, we are "they" and "they" is us. There's an entry for the grammar police and philosophers to chew on. [Hope you all enjoyed the Princes Bride reference.]