NSA isn't hurting for money. They're just going to monitor those transactions for suspicious activities. As long as you're not doing business with a terrorist, you have nothing to worry about. If you are doing business with a terrorist... is that a Reaper drone I hear?
It's only guys like SBF you gotta worry about ripping you off.
If you can figure out how to teach those sorts of people to say "no, I think I've actually got enough already" then please let me know, because I've been wracking my brain trying to solve that one for a while now.
that's... not how that works. all you can do with 51% is possibly double-spend whatever coins you already have. or undo some transactions.
so you submit a transaction, then use your extra 1% of hash power to mine a new block that says you didn't actually spend it. at the same time you need to trick somebody else into believing you actually did send the coins, and take their stuff you "paid for." then after you have the stuff, you can submit the block that doesn't have your transaction in it. Voila, free stuff and you didn't spend your coins.
it does not enable you to mess with other's balances. other than possibly reversing some transactions. you would need the private keys to their wallets to take their money. and if you have those, you don’t need 51% of the hash power, you can just take the coins with 0% hash power.
It's obviously not a comprehensive guide on how to cheat the system. I'm making the point that computers will never be secure under the current paradigm when there are massive and powerful actors with vastly greater resources than the average person. I strongly suspect that an org like the DoD (which had exclusive access to integrated circuit technology for three years before anyone else) could probably capture/spoof virtually the entire network if they wanted too.
By spending billions of dollars in order for them to dupe a transaction worth a couple million at most. Once. Before the entire network realizes what happens and a fork is made. It's just idiotic enough to work!
Ignoring the fact they definitely have the resources to sustain it, how many people will continue to run a node after losing everything to such an attack? How will anyone reclaim real world value if they exchange the coins for something else?
Coin holders would only lose everything for as long as the attack occurred. The validated chain would still correctly record their claims.
The people receiving the fake coins transfered during the attack are the ones that will be pissed. Any goods or services exchanged during that attack period may not be compensated.
Again, how many ordinary people will continue to run a node for a network where they have nothing for an extended period? Even if they do, will the value of the coins remain even after such an event proves the weakness of the system?