You can see the current Steem witness list at https://steemd.com/witnesses and https://steemian.info/witnesses
Thankfully Steem voting is stake based to prevent just that sort of one-user-one-vote sybil attack. He's currently appealing (begging) different communities to get more votes for his sockpuppet attack witnesses. And as this post explains he was able to get exchanges to power up their customer's funds and proxy to his voting account, even though those exchanges should know better and perform due diligence before doing something like that.
So he still has 11 witnesses in the top 20 as of right now. I can't believe that Huobi and Binance would do that, it seems SUPER unethical to me. I stopped using Poloniex like three years ago just because it was trash but I guess it's no surprise there. Glad at least Binance did the right thing. What's going to happen now?