Why are illegal drugs illegal?

Because it is illegal to hand out drugs to people (including kids underage) in other states which is why our Government doesn't allow it and it can kill you.
And the fact there are too many people in the world who sell Crack and Weed anyway and still get away with it.

Because they can potentially harm 你 and people around you, they are extremely addicting, and can possibly kill you.

Because they're too potent and can harm 你 and your vital organs.

If illegal drugs weren't illegal, it'd be a paradox.. because the illegal drugs would be legal.. *Chose to put confusing answer rather than one that makes sense.*

BUT, if I answered seriously...I'd say it's to protect society in general.

Because hering communicate with each other 由 means of farts. ;)

This is actually true.

Because their addicting and can kill you. Duh.