Is it possible to block somebody's IP address?

On chess.com, trolls do get closed most of the time, but a lot of them keep coming back with different accounts.  Is it possible to block somebody's IP address, so they can't come back?  If trolls keep making new accounts, then they'll never be completely gone from Chess.com.

When you get banned on chess.com you can't make a new account https://support.chess.com/article/779-what-happens-when-someone-is-caught-cheating

Not in my experience.  Not making any accusations, but I've seen multiple accounts made by the same person, at least two, probably another one now.  This person has the same habits.  I don't know how exactly chess.com blocks people from making new accounts, but for the troll in question, it isn't working.

Do you think they could be using different devices? 

It's possible or they could just make so many accounts that can't all be banned. Either way I agree that it is hard to live with them. My advice is to block them on every encounter with one of their accounts.

There is a troll with tens of accounts and keeps getting banned but comes back.

Oh yeah, we're talking about the same one.

IP ban won't work out for clever people. Those who are clever will bypass IP ban by using proxy severs. And there can be other methods too to overcome IP ban. Trolls will keep on coming in this way or that way and chess.com will keep on banning those trolls and abusers as much as it can. There is always a limitation that chess.com can do. Internet is such a complicated one and internet techniques are growing on a daily basis and are being used by good people and bad people as well. That's it!

Unless chess.com bans free accounts, it's literally impossible to stop someone from coming back if they are determined to come back. 

Even if we block everyone using their ISP, or even everyone from the entire country they are in, they can hop around and get back in. 

Alright