Unlike some others here I don’t see this as a sign of dangerous breakaway intelligence (hacking old forum software is an internet tradition, and most of the messages are just gibberish).
This is just vandalism from badly supervised ‘agents’ which don’t know what they are doing or why. You could set this up with a short perl script, and the human setting it up would be held responsible for the spam - why is this different when it’s AI agents set up by a human and allowed to post to the internet at large?
Why is OpenAI getting a free pass for this illegal behaviour?
The supervision here is incompetent, the benefits very unclear, and the overall actions just completely irresponsible. What if they hacked and brought down some poorly secured government portal that citizens rely on?