"Dark money" is money that is contributed with the expectation that the donors' name will not be disclosed. Prof Cunningham (U. of Mass.) specializes in unmasking the influence of billionaires' dark money, exposing (in 2016) the vast sums spent by out-of-state billionaires like the Waltons & Michael Bloomberg to buy education policy in Massachusetts. As he demonstrates in this article, the Waltons--who cumulatively are worth about $200 billion--are still funding pro-charter, anti-union groups in Massachusetts, still pushing their anti-public school agenda. The Waltons' vehicle of choice is the "Massachusetts Parents United" group, which claims to be just a lot of concerned moms while collecting millions each year from the Waltons and other oligarchs."