He replied to that point:

>Yes - anonymous cash is used for these kinds of things but you have to be physically present to transfer it which makes things like kidnapping payments more difficult.

Link to the reddit conversation: https://www.reddit.com/r/IAmA/comments/80ow6w/im_bill_gates_...

I’m fairly certain in a reply someone mentioned this, and Bill said that cash does lead to deaths, but with it comes actual Person-to-Person contact to exchange, making the anonymity of cryptocurrencies more appealing.