If you have tried to use steemit.com the past few hours, you might have noticed this error:
Steemit, Inc. issued a quick post to notice us there was a big DDOS attack on steemit.com which ended up with the website being inaccessible and now intermittently accessible, even if the attack is over. That of course will be fixed soon.
But lucky for us on Steem is that we have so many interfaces we can use to access the blockchain, and Steem blockchain is unaffected by a DDOS attack on a user interface. While steemit.com website was/is down, anyone can use a different dApp to access the blockchain and do whatever they need to do on Steem.
You might want to give steemit.com a break for a while, before they are fully back, and use an alternative like busy.org or steempeak.com or the more specific dApps out there.
Anyway, this DDOS attack comes at a time when certain accounts post a lot of spam on our blockchain, and I mean bot spam (check 
To be honest, that's a good thing. Firstly, because we can learn from these experiences (no theory beats practice). And if there's something to improve, we have more data that will allow us to know where we should do so. Secondly, because that's one more way Steem gets on the radar.