We as PALnet, can't.
It requires the active authority of the token holder to transfer them, enforced by the publicly visible smart-contract on the Steem-Engine sidechain.
This chain has multiple nodes already. Though...
Currently, due to the new age of the side-chain and the project, it is being run on a single master-node, run by Steem-Engine themselves. They in theory could do what you say, but as that kind of thing would ruin everything they have built, it wouldn't make sense for them to take that action.
They are moving towards a consensus system on these nodes. It should be fairly soon, though I don't have a time-frame from SE. I know this would be considered a fairly high priority for any sort of long-term of the project.
So when I said that "we can't", we as PAL can't. SE currently can, but it would be public, self-destructive, and pointless to do to an individual. They also won't have the ability to forever.
A little bit of trust in the early days while the safeguards are properly built is never a bad idea. In the meantime, the smart-contract for the token is publicly available to view. As is the block activity for the side-chain.
We do love the skepticism and the questions. Keeps everything as honest as possible.