Excellent points about data loss, and how the blockchain can help prevent it. This actually isn't merely a question about how the future can use the blockchain, but this is something currently being used.
@aggroed just posted recently about researching the account @freedom, which information he was able to ferret out of the blockchain.
I am sure forensic scientists for the FBI et al, will also find it useful. It also makes the monstrous server farms of the NSA and their ilk superfluous, and if we can force government to use blockchain, then the citizens will have the same power that government is wielding to parse metadata, and specific information. They're doing it using our sovereign authority, so there's no excuse to keep us from doing it, too.
I have long been pointing out that all of the surveillance technology being used against us will soon be used by us against them. The blockchain can be a huge equalizer in the battle against government corruption.
Let's make all government agencies use the blockchain to store their emails. That would solve a lot of problems. We wouldn't need phantom Russian hackers to find our chief criminals deleted emails next time.
The thing we must remember is there is no "the blockchain", there are many. The steem blockchain and many others are very open, though some are not. They don't have to be open at all to still be blockchain based, so we need to be careful what we ask for as blockchain is a tool. As with any tool it is possible for them to be used for malevolent or benevolent purposes and we simply need to focus on steering this towards use of a blockchain that is OPEN (like steem, or EOS, etc)
Good point. Let's get the gummint to use an OPEN blockchain for their communications, so we can keep an eye on them.