It’s from New York, and it would require large social media companies to let third-party services do things including blocking or muting content on behalf of users — basically mandating a certain level of free, open API access. Mike Masnick has some thoughtful analysis:
In effect this would roll back some aspects of companies like ExTwitter and Reddit trying to restrict access to their APIs and putting up ridiculously expensive paywalls for that access. It would be tearing down walls and enabling more innovation. [...] I like the concept of the bill, but I’m just not sure New York really has the authority to do this like this, and I worry on the margins about some of the way the bill is written.