Despite several high-profile tax schemes being unraveled by federal agents in recent years, Iowa Senator Chuck Grassley says many companies and individuals are still working to cheat the government. Grassley, a Republican, is chairing a Senate Finance Committee hearing this morning on what he says are abusive tax shelters and the government’s response to the problem.In the wake of the Enron scandal, Grassley says the government is making some progress though he says “the I-R-S needs to make better use of its resources to go after illicit tax shelters.” Grassley proposed legislation months ago that would target such illegal shelters, where people and corporations try to hide income to avoid being taxed on it.Grassley says he intends to expose any weaknesses in the government’s enforcement efforts as the buyers and sellers of illicit tax shelters continue to find new, creative ways to ply their trade. He says such law-breakers cost the taxpayers 50-billion dollars a year in lost revenue.