So mastodon.social was under a DDoS attack.
@Gargron confirms this.
Someone out there doesn't like the Fediverse.
But also, if they thought that taking down mastodon.social would take down the Fediverse, then they were incredibly foolish!
The Fediverse is built on redundancies.
This isn't like Twitter where a Fail Whale would bring down the entire social network.