Sorry I don’t follow.

Is 4 a bin or a bag?

Is everything in 4 bagged or only the plastic?

How does bagging the plastic avoid it being left out in nature or burned?

The short answer is, it is free - they’re asking for a contribution but most people would enter a custom amount of $0.

There’s a longer answer about what free means in different contexts and how that pertains to opensource, and a longer answer about how “free” things have led us to the internet we have today, but I don’t think you’re asking about either of those things.

We’re being harassed for having common sense

There’s a lot to unpack here.