Cans? Really?

Okay, I see posts on here all the time about cans, and I don't get it. Where would one possibly get enough cans to make them worth a trip to the yard? I see "I took my cans in" pretty regularly on here.

The few cans I get come from my groceries, and they just go into shred. Sounds like you have a different category for cans. Is that correct?

And where do you get enough to make it worth a trip to the yard? Are you talking about raiding curbside recycle bins? That seems problematic on a lot of levels.

Enquiring minds want to know...