> The frontier labs can monitor the behavior of agents for millions of customers (did you try hacking with frontier labs? Good luck), but they can't secure internal use?

They "monitor" this by having classifiers watching the model output that'd stop the session/punt you to a weaker model/raise an alarm if they see anything suspicious. They can't do that in a cybersec eval because the normal safeguards would just be going off at all times.

Why didn't they attach a special classifier, which'd allow hacking-within-the-task but not going off the rails? Good question; part of the answer is obviously "it's hard to have a classifier that smart" and "it'll have false positives" but even a very bad safeguard would have stopped this.