You'll have to go into your security settings to block someone from posting in your threads.
Exclude users to respond to forum

My Home à Account à Privacy
And now? On the bottom off the page I see
BLOCKED MEMBERS
Blocked members will be unable to post on your Notes section or send you Messages.
Will adding a user here prevent hem/her to respond to my forum posts?

Although it has already been answered some more information:
http://support.chess.com/Knowledgebase/Article/View/38/1/how-can-i-block-another-user
So a blocked user can't do
- post notes to your account
- send you messages,
- accept your game seeks
- be auto-matched with you in open seeks
- join tournaments that you are running
- post in content that you created

Related question: If I have blocked someone, and then I post in a topic that someone else started, then can the blocked individual "quote" me or respond to my post in any way in that thread? Will the blocked individual even see my post? Just curious.
Related question: If I have blocked someone, and then I post in a topic that someone else started, then can the blocked individual "quote" me or respond to my post in any way in that thread? Will the blocked individual even see my post? Just curious.
i don't think blocking has any affected on threads not created by the blocker.
In this topic
I posted a few times.
However soon I got disgusted by the tone of voice from the OP.
I felt the need to say so in an unfriendly manner instead off leaving the thread alone. (post #142 for those interested)
Now here’s the thing, after the OP threw some random insults and false statements to me (#145), I cannot respond on this topic anymore.
I am not banned from the forums or anything, so I conclude that the OP has blocked me.
Does this mean that if you put someone on your list of blocked users that (s)he cannot comment on your forumtopics?
That would truly be great.