From the same MJS article I earlier linked to:

“The public release of this John Doe evidence without court authorization is not merely a violation of the John Doe secrecy order; it is a crime under Wisconsin law,” Chisholm said. “As Special Prosecutor Fran Schmitz has done in the past when other secret materials have been publicly disclosed, we support any effort that may be undertaken to determine the source of these newest leaks.”

Such an investigation appears possible.

GOP Attorney General Brad Schimel “is currently reviewing the available options to address the serious legal questions raised by the leak and publication of these sealed documents,” Schimel spokesman Johnny Koremenos said in a statement.

State Rep. David Craig (R-Town of Vernon) said he wants to form a special legislative committee with subpoena power to look into how the investigation was conducted and the leak of documents. Craig, who is running for state Senate without opposition, helped lead the effort to end the ability of prosecutors to use John Doe investigations to investigate campaign finance matters.

This leak of John Doe documents comes just weeks before the U.S. Supreme Court is to meet in closed session on a petition from prosecutors to revive the investigation.