They're under a _DDOS_ attack. Assuming that their Facebook account, Twitter account as well as website was compromised just so the hacker could create a post announcing Richards's firing is a bit much, I think.
I wonder if this (the possibility of SendGrid's website and every social media account being compromised) isn't the only motive behind the deletions. Maybe the mods are looking to avoid drama or protect Richards? I don't know. If their stated reason is their only motive, will they bring the posts back to the front page once SendGrid confirms?
> Assuming that their Facebook account, Twitter account as well as website was compromised just so the hacker could create a post announcing Richards's firing is a bit much, I think.
That is what DoS attacks were originally used for. Hose the target, then run your attack. It was more typical for attacking clients trying to use network services. In this case it's a PR blitz meant to look like an authentic message.
Facebook and Twitter taken over takes a while to get back into the hands of the real owners. If someone got a fake message cached by cloudflare and then took down the backend, it could leave a false message hanging around until the target can get the service restored.
Why the hell would someone do this? Who knows. Probably a dejected neckbeard with mental problems who feels like causing a shitstorm.
It's possible that the server that was compromised also held access to their Twitter and Facebook account. Depending on what backend they might be using, they could have it configured to allow posting to social media through a control panel rather than through facebook.com or twitter.com. In this situation, a compromised backend control panel would mean an attacker has access to their social media accounts as well. I've seen similar attacks first hand in the past.
http://venturebeat.com/2013/03/21/breaking-adria-richards-fi...
A look at Richards' personal page also shows a CloudFlare DDOS splash page before serving up the site.
The assumption that they're under attack is reasonable. What's true today will remain true tomorrow.