"If you've seen firsthand what a drug like meth does to a person, it makes you think twice about the ideal that everyone has the right to put whatever they want

"If you've seen firsthand what a drug like meth does to a person, it makes you think twice about the ideal that everyone has the right to put whatever they want into their body/mind." It's been stated in other replies, but it bears repeating: this argument is nonsense. You can use the exact same reasoning to argue for banning anything that has ever caused harm to people (which is pretty much everything, ever).