How To Remove Yourself From A Chain Message in Facebook

I'm not sure if this will help, but saw this from Facebooks' Help Center:
To unsubscribe from a conversation:

1. Open the conversation.
2. Open the Actions menu.
3. Select "Leave Conversation."

The other people in the conversation will be notified that you left and you will no longer receive messages from the conversation. Note that you can only unsubscribe from group conversations — you can’t leave one-on-one conversations.


Note: Its NOT certain if this is applicable for mobile users