Former presidential candidate Ralph Nader is taking up a new cause … something he’s known for doing from time to time.

This time, he is targeting Fannie Mae and Freddie Mac’s treatment of investors several years back, sending a letter to Treasury Secretary Jacob Lew saying the GSEs’ shareholders have consistently been left out in the dark.

The Albany Tribune published an article on Nader’s letter this week.

Nader objects to how the delisting of Fannie and Freddie’s stock from the NYSE caused the agency stocks to tumble years ago. He also suggests statements from numerous government and agency officials leading up to that moment painted a picture of stronger enterprises, when in fact investors faced significant risk.