The Attorney General was given notice that a plaintiff was challenging the constitutionality of the state’s minimum mark-up for gasoline sales in Wisconsin. The attorney general did not intervene in the case, but later sued the defendants for violations of the Act. The defendant argued that the Attorney General should be collaterally estopped because he was given notice and an opportunity to intervene in the prior action. The court held “there is no authority for the proposition that a governmental entity provided notice of a constitutional challenge to one of its statutes in the context of private litigation must intervene or suffer the consequences. “While the Attorney General may have a general duty to defend Wisconsin statutes against constitutional attack, this does not mandate intervention and justify the application of preclusion principles. For better or worse, intervention is a strategic decision left to the better judgment of the Attorney General.”