There are no locks. It will roll away if your floor isn't flat, as demonstrated here: https://twitter.com/MKBHD/status/1232708514625310721

Next up, $500 machined aluminum wheel blocks.

My first thought was... why not just wheel the computer out?

My second thought was... comes back to find computer up on cinder blocks, wheels gone.

You can't just pop them off, they're screwed on from inside the case.

No locks. https://twitter.com/MKBHD/status/1232708514625310721

No mention of locks. This first iteration is obsolete by design and will eventually be replaced with a new version with locks in another Apple line up. Who knows on what the price that would be.

The lesson here is to not purchase the very first iteration of Apple products. Sometimes it can turn out to be an expensive sunken cost.