That's Mastodon, a Twitter-like social network that has had a massive spike in sign-ups this week. And its development costs are paid for by online donations, rather than through the marketing of users' personal information. If you later decided the app was no good, you could just take back the key. What makes this model possible is the blockchain, the underlying technology that supports bitcoin. But the supporting blockchain technology is a powerful record-keeping and transaction system that opens the door to much more than exchanges of money.

Source: Washington Post March 23, 2018 14:21 UTC