Twitter (and Facebook) might have problems and ill effects on large numbers of people, but they are a reliable way of getting a message out to a group of people

Twitter (and Facebook) might have problems and ill effects on large numbers of people, but they are a reliable way of getting a message out to a group of people--in the case of Twitter, to anyone (even if you don't have a Twitter account, you can visit https://twitter.com/AccountName https://twitter.com/AccountName for updates). Could the government have built such a system by commission for the public good (after all it was directly involved in the Internet, the substrate thereof), or is this something that was only able to coalesce with private capital, markets, and profit motive?