stream_item

Called for each item processed for viewing by conversation();

The hook data consists of an array

    array(
        'mode' => current mode of conversation()
        'item' => item being processed
    );

    Set item['blocked'] to block the item from viewing. This action will not affect comment or sub-thread counts, so if there are three comments in a conversation and you block one, three comments will still be reported even though only two are visible.