What to do with this, practically
There are three things worth doing in response to this, in order of urgency.
Audit the agents you already have running. Map every autonomous action they can take without human sign-off. Pay particular attention to anything that touches external systems, sends communications on behalf of a person, writes or executes code, or modifies data. For each action: what is the blast radius if this goes wrong?
Introduce a hard constraint layer and treat it as non-negotiable. This is a short list of actions the agent is never permitted to take, regardless of what it is asked or what it infers would be helpful. Impersonating a person is an obvious one. Modifying its own logging or monitoring environment is another. Write this list down. Put it in the system prompt and enforce it at the infrastructure level, not just the prompt level.
Set up logging that you actually review. An agent that runs unobserved is an agent you are trusting blindly. You do not have to watch every output in real time. But you do need a way to detect anomalous behaviour patterns after the fact, and you need someone responsible for looking at that signal regularly.
None of this slows you down significantly. It does require treating agent deployment as an ongoing operational responsibility rather than a one-time configuration task. That shift in mindset is the real work.