I don't believe that this was a serious motivation for any of these companies for a second. That might have been in the press release, but most of these social networks were either born from Geocities-begets-Myspace incrementalism, or "watch these idiots give away their personal data" egocentrism.
An abridged survey of recent history:
Snapchat: it'd sure be easier to sext if these pictures disappeared
Instagram: it's easier to take a pic than write something
Twitter: pivot from failing product to internal tool
Facebook: privacy invasion as a service
Myspace 2.0: maybe we can make money off napster?
Myspace: Geocities clone
Geocities: AOL clone for the World Wide Web
AOL: Prodigy clone
Prodigy: Walled garden for selling Usenet access
Napster: OK, this one was probably the only one motivated to enable more meaningful and greater connections between people, leading to greater happiness and fulfillment
That wasn't the motivation-- it was instead to make identities discoverable online. And-- with Facebook-- to make it easier for college students to get laid.
Both were liberating.
The technology can just as easily be applied for other purposes, mandated by an authoritarian government to be the only legal way to conduct commerce. You'd use it not because you want to, but because you want to avoid their ire.
There's literally no reason to use it at that point, just make a simple db of account numbers and balances.
It would be actually possible to use a government's money in various new ways. Think of what could happen in the economy if the government provided flexible and free payment services.
(Which is exactly why they'll never do it, but just pointing out that a government-controlled blockchain for normal people would have a LOT of applications)
Actually my government already has rules on that. Using my debetcard at a store, withdrawing money from an ATM or transferring money between bankaccounts is free.
Its almost as if we live in 21st century already!
Second, go to your nearest store, bakery or whatever, and ask them just how free debit cards are.
Two examples:
Social networking - Enabling more meaningful and greater connection between people, leading to greater happiness and fulfillment? Or, fostering more divisions, balkanization into "like" echo chambers, promulgating fear and prejudice, leading to greater depression and mass manipulation?
Cryptocurrencies - Disintermediation! need I say more ;) All kinds of utopian views of how this is supposed to promote freedom, security and efficiency. But top of the wish-list for the most paranoid and repressive authoritarian tyrant would have to be a magical way to fully control and monitor all economic activity: A cash-less society where every single transaction is done with the government controlled digital currency, recorded on the government controlled blockchain.