The blockchain will be hacked. As companies and governments adopt it will be part of the usual quantam computing is already trying and some say it has been done.
The problem here is that 99% don't have a clue about what it is they're talking about,
IMHO the number of 'programmers' working to 'hack' bitcoin is 10to1 to the number of people just mining the art of 'hacking bitcoin' is a much more interesting problem than just 'mining'.
The 'hacking' of BITCOIN is an industry,
Last month I wrote an entire article here about how to 'hack bitcoin'
It's being done, the 'hack' of NICEHASH in past 24 hours ( $62Million USD) is a classic example aka 'mt-gox', happens all time and its ignored, ignored until its all gone.
I would not worry much, there are 2,000+ BTC clones, and one of them say zencash or monero will gladly fill its place if&when BTC gets easily hacked
Most likely problem is this sodom&gomorah/tower-of-babel problem like we have now 1,000's of blocks, and wallets in a sea of mis-communication, all be ran by common criminals ( nicehash/mt-gox, ... ) and their whores.
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Problem with 'hacking bitcoin' is no two morons agrees, IMHO 'hacking' means programming, it means typing on keyboard, thus ALL misdirection of BTC is hacking,
There is wallet snatch&crack, there is keyboard sniffing ( russian porn industry ), there is brute-force private-address ( brainflayer ), there are algo's for all mined coins to go after different dimensions of 'hacking btc', I would suspect a ten volume set of books could be written on the subject, trouble it would be out of date if not completed within a month
For now most interesting of areas of BTC-HACKING IMHO are attacking private keys owned by high-value accounts, that's where the money is, that's where the real work effort goes by the pro's.
Almost all these high-profile rip-offs like mt-gox or nicehash are 'inside jobs', so not 3rd party hacking, but guy in mom's basement, but more likely just a normal in-house 'worker' getting his share before their PONZI collapses.
BLOCKCHAIN technology is here to stay
PRIVACY is probably most important issue, completely ignored by everybody associated with BTC, who clearly just care about MONEY, and don't give a shit about crypto-anarchy.
Satoshi would PUKE on what has become of Bitcoin.
Satoshi is dead or in prison, as dead men tell no tales.
Today 'Bitcoin' is just an amalgamation of morons and criminals, say the recent "BITCOIN GOLD LAUNCH" BTG by Russian/Chinese mafia, that's the essential element of todays BITCOIN WORLD.