Mormons are required by Commandment of God to pay 10% of all their GROSS income to the LDS church. This includes all income - including: employment, unemployment insurance, student loans, pell grant checks, Social Security income, Medicare, foodstamps, trust funds and any other form of income, even including finding money on the ground.
And what happens if they don't pay it? Does the church send thugs to beat it out of them? Do they have to go to church jail? If none of that happens, its voluntary.
There are a lot of things that my wife's church requires by commandment of god her to do. She does some of them. She has had some visits from the church deacons, but they have yet to force her to do anything.