car companies are hoping that the switch to driverless cars will result in fewer crashes. however, let's say they run on a cloud network (because they'll have to) and said cloud gets hacked. this could result in the worst pile up in an entire economic sector.

something to do with hacking, but also as to why trains are better

Digital currency can't be hacked due to its nature. Read up on it.

I have . The currency itself is rather safe, however..... user wallets and transactions are highly susceptible to hacks. So far this year over $6b hacked.
It's safe as long as you dont have any or try to use it.
Faaks