Hah that's classic politics "Hello John Q. Public, here's all our data! It speaks for itself" John Q. Public: "Wow, you really improved last few years homicide-wise" "And so you see, a third party unrelated to us has just confirmed what a great job we're doing with simple empirical, evidence-based governance!"

So that means what you want to do is specialize in identifying bias in these datasets and finding the smoking gun. Such a task can be an ugly business but necessary for the public good, pushing data sharers to either share good data, or not share, but not share tricksy data in this unethical way.