Conspiracy theories, my foot... 🙄
Look, anyone with half a brain who knows how to navigate vBulletin can figure out that users can leave notes on one another. We know how to use them. But those notes are meant for technical housekeeping—stuff the software should be handling automatically but fails to do. I'm talking about logging rule violations or tracking username changes. That accounts for at least 95% of all entries. Anything else is incredibly rare.
To ease your mind, here is what those "secret" notes actually look like:

There is no grand, systematic effort to document "forum crimes" or any other nonsense. 🙄