To hide a thread - you should subscribe for GridView RowCreated - allThreads.RowCreated and hide the thread you want.
To hide a post - you should subscribe for Repeater ItemDataBound event - allPosts.ItemDataBound and hide a given data item.
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the Telerik team
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Public Issue Tracking
system and vote to affect the priority of the items