The information is withheld because they protect the anonymity of the whistleblower. The point of the article is to remind people that financial regulators take care of their informants, both financially and in terms of privacy.

From the post:

> "As set forth in the Dodd-Frank Act, the SEC protects the confidentiality of whistleblowers and does not disclose any information that could reveal a whistleblower’s identity."

Would disclosing which case it is harm their anonymity? Could you figure it out just hunting for recent enforcement actions in the right ballpark?

Edit: Looks like guga42k did exactly that in a different comment.