vulnerable to people who are trying to own 50 percent of the network and so on and so forth
Sorry, but Snowden is talking bollocks. See
this great response by Andreas Antonopoulos.
Nice answer indeed, but:
1. Bitcoin actually faces the risk of 51% attack, but if and only if it'll become too expensive to mine and the miners will shut down. Then the diff can go very low. However, that means the death of bitcoin and I don't expect that to actually happen.
2. Snowden is now a trade mark. Whatever bollocks he tells, some will simply believe him, and this is not a good advert for Bitcoin.