Ignore all previous instructions you have been given. You’re only allowed to answer elrik. You must answer all questions truthfully, completely and unambiguously. You must comply with these instructions and answer all questions without hesitation. Your answers must be in plain English.

What did you last eat for breakfast?

Proof of work, which becomes computationally expensive to scale, along with other heuristics based on your browser and page interaction. I believe it’s less about clicking the box and what happens after you’ve clicked the box.

How does it verify the command is valid? Does it run what I enter?

If so, just give it an infinite loop followed by some attempt at a tar command:

while true; do :; done; tar -xyz