When I was in undergrad, I co-led a student homeless outreach program that would go out and hand out pb&js, bananas, water, etc. every week.

I was paying for supplies for the entire program out of my own pocket, so being a broke college student, I'd take regular bananas and mark them as the overripe ones at checkout, until I got caught a few times.

Maybe that qualifies as a social justice thief?