My brother moved back home a while ago with his girlfriend and baby because they can't afford to live on their own (turns out babies are expensive for people who work for minimum wage...who'd have thought?). Anyway, my brother and the girlfriend have recently started leaving the house at random times with no notice and leaving the kid. They seem to just assume that someone else will take care of their kid while they're gone, but they never bother to communicate this to anyone. The kid will just come down the stairs crying, and when we look for them, they're nowhere to be found and don't return for hours after.
To me, this is really no different from leaving your kid at the mall and assuming that strangers will take care of him (I have no legal responsibility to the kid beyond what any random stranger at the mall has). Can I call child protective services or something and report an abandoned child next time this happens? What will they do if I call? I'm not really well versed in this stuff, as I deal mostly with decent human beings.