It's not. But, that's the unintended (or perhaps intended) war on drugs has left us with. I'm not one for legalizing or even decriminalizing drugs, but some of these laws that have been passed to fight drug trafficking only hamper honest citizens who are engaging in no criminal activity.
In some states, transporting large sums of cash can be used as prima fascia evidence of a drug transaction - just cash, no drugs. And as such, the money can be confiscated and the car impounded as part the "forfeiture" laws. It then becomes the citizens obligation to prove the money isn't dirty, rather than the other way around. How this isn't unconstitutional, I have no idea.
>In some states, transporting large sums of cash can be used as prima fascia evidence of a drug transaction - just cash, no drugs.
So then, I guess you’d never want to sell your house for cash so you could move somewhere else right-quick?