The best way to stop the Mormon cult from harming any one else's live is to stop paying them. Do what you can to stop your family members from paying them, and do what you can to discourage your friends from paying them. Church members who are not happy with their church and former members who recognize it for what it is (a cult) can stop this craziness by simply stopping their cash flow. In addition, don't listen to what the church leaders say because they'll just lie to you and you'll end up paying them eventually.

I think it's fair to completely reverse the current paradigm by not cutting anyone a break who pays tithing to the Mormon church. Treat it like they have a bad gambling habit. If you've got a friend or family member who can afford to give their money away to the church, then perhaps that break you're giving them on the rent, or the help you give them in other ways needs to disappear.

Personally, I donate a fair amount to the United Way because I want to help those who are less fortunate than myself. The people who are helped aren't forced to believe what I believe to get the benefits. They don't have to associate with a cult and its members as a price to feed their families. All they need is to have a real need that they can't meet on their own. A neutral organization reports to me on a regular basis so I can see where my donated money is going. I don't have to blindly wonder what the money is being spent on. Why feed a corrupt, self-serving business empire that masquerades as a religion when you can really do some good? We should start a "just say no to tithing" campaign on this forum and see how far it goes. If you feel the need to donate to help those who are less fortunate, there are a lot of registered charities out there who have full transparency. You don't have to give your money to a cult or worse yet, fear what'll happen if you don't give them your money.

Kindly set a rule in your household that anyone who can afford to give money to the church needs to fully support themselves first, or they've got to move out, give up their allowance, contribute what they make to the family, quit college and get a job to pay their own way, etc.. To be fair, you could even show them reports from the United Way or an other responsible charity. Tell them you demand full written disclosure of where the tithing money goes before you will let them pay tithing. Maybe this is just another opportunity to teach a life-lesson to those you love.

Go steal all your family and friend's money so they can't pay tithing anymore.

You know what's funny, I can do more in my spare time for free to help somebody over a week than I could ever do with tithing in the same time period.