system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are cigarettes legal?

I just can't wrap my head around it. They are known to cause cancer and to contaim a large amount of toxic materials, so how come are they still legal?
gpt
An extremely powerful lobbying group and most importantly, the government makes oodles of cash taxing them. 

It's also important to recognize that "second hand" smoke wasn't well studied until recently, so if you were only hurting yourself then shouldn't you have the freedom to do so if you choose? This is why you see so many states passing public smoking bans within the last decade or so.