I'm kind of curious what it means to run a non-profit as a front. I sorta know from news/pop culture that a lot of rich people use non-profits as a way of funn

I'm kind of curious what it means to run a non-profit as a front. I sorta know from news/pop culture that a lot of rich people use non-profits as a way of funneling taxable income into championing their own causes and throwing galas for themselves. But it sounds like Singer was using it more as a money laundering front? Or was he basically paying himself an exorbitant amount to be an executive of the non-profit, while not really doing much? Is it really that easy to abuse the non-profit system in the US?