Obviously 501(C) exeptions are abused sometimes (that's the one churches use). What would you suggest?

Our public funding is tight, and essential services like road repairs, emergency services, etc are facing cuts that end up degrading our quality of life. Meanwhile, tax exceptions are given to organizations that do little but fund Richard Roberts' houses, cars, and horses or Charlie Sharp's dairy farm and personal town. How would you suggest the law be changed to allow for tax exemption of honest non-profit organizations and weed out the scammers?