Final answer:
The most helpful data you might get from Usenet on a person you are investigating is negative comments made by others about your target.
Step-by-step explanation:
The most helpful data you might get from Usenet on a person you are investigating would be the negative comments made by others about your target. This can provide valuable insights into the person's reputation and how they are perceived by others. While postings by the individual you are investigating can provide some information, it is important to keep in mind that people may present a biased or false image of themselves online. Criminal records posted can also be helpful in certain investigations, but it's important to verify the accuracy of such records and not rely solely on Usenet sources. Lastly, security tips to help you investigate may not directly provide information about the person, but they can offer guidance on conducting the investigation safely and effectively.