Ms Ellipsis: What's the worst thing about your job?
Teenage Girl (rolling her eyes): Having to talk to Randoms.
Ms Ellipsis: Randoms?
Teenage Girl: You know, Randoms, people you don't
Tough problem for a person working in the hospitality industry.
The closest reference I've found to Random in this context is the Macquarie Dictionary's definition No. 7:
a fool; an idiot: that guy is such a random.
But this was used in the context of unknown. Or perhaps all "unknowns" are, by definition, idiots.
UPDATE: Further definitions of Randoms found here :
random: a dismissive description of an uninteresting and unimportant person... can also be used to describe an odd or amusing situation
Example: Person A: How was that party last night? Person B: Ehh,
it was okay...it was mostly a bunch of randoms. Or, What the hell was that? That was SO random!
random: An unknown person (stranger). Example: We met a few randoms at the party last night.
and also here: random