It might be similar to Matt Godbolt's experience with his "Compiler Explorer". Most of your users are not trying to set fire to the free system, and when somebody does, on purpose or by accident, you focus on being able to reliably recover, not prevent it. So e.g. maybe Clara T Vandal "cleverly" seizes control of a random Compiler Explorer build box, well, that box is no longer marked OK because of her changes, it gets automatically torn down and replaced, no real problem. Did Clara do 0.001¢ of Bitcoin creation without paying for it? Yeah, maybe, and Clara probably cost Matt 0.1 cents for the data centre fees but it's not a big deal.