And remember, data can still golden even if it is hidden in dung. They are many ways that users can be evil and twisted. A user might spread bad news about you to their friends and family. Negative words carry a lot more weight than good words. And, if the evil person is talking with friends and family, there is a trust bond.
People love dirty laundry.
They love gossip. To many people, evil gossip is much more fun to spread than good gossip. A user might try to hack your web site or server. A user with only your server log files can do a lot of damage. They can hunt down folks that are sending you referrals.