If you've got a link to that law please share, though what we're talking about is ownership that provides control. Dividends don't constitute ownership and control; think-- savings bonds.
directors are involved in formulating monetary policy
Sort of. What they do is participate in the activity of the setting of monetary policy (from here). The FOMC makes policy. If Congress doesn't like the FOMC's policy then they can abolish the Fed. The stockholders have about as much control as someone who writes a crank email the the Fed -- which is yet another form of participation in the activity of the setting of monetary policy.
Here
The mention of the 6% dividend was in direct rebuttal of your comment that these weren't really stock because, in part, they didn't pay dividends.
The FOMC makes policy. If Congress doesn't like the FOMC's policy then they can abolish the Fed.
The FOMC is made up (in part) of 5 of the district bank presidents. Really it is 4 members plus the head of the NY FRB but that is neither here nor there. District bank presidents are elected by the district FRB bank's boards of directors. Recall that the majority of District bank boards are appointed by member banks ie: stock holders. In other words shareholders determine 5 of the 12 members of the FOMC.
Congress could abolish the FRB but the economic problems that would cause would be quite extreme. Much more likely is that Congress would legislate a change to any of the FRBs decisions that they don't like, but I am unable to find an instance where they have. What that means in reality, as opposed hypothetically, is the FRB sets monetary policy.
The stockholders have about as much control as someone who writes a crank email the Fed.
As 5 of the 12 directors that determine monetary policy are (indirectly) appointed by shareholders I believe this statement to be wildly erroneous.