Blocking someone on Xbox live usually happens when some users start harassing others. There is no surefire way of blocking someone but there are steps that can be taken. It is a free world and submitting a reason for blocking will be reviewed by the Microsoft team before a block is applied. What happens when you block someone on Xbox live
When you block someone and it becomes a successful block. If you submit a negative review of the person, the chances of you ending up in the same games again will be reduced. If you have blocked them they won't be able to send you messages or see your online status. And if you block a user, then you automatically mute them, so they wouldn't be able to hear you in a game.
How to block someone on Xbox Live
You will need to click on the gamers tag and send a review as to why you want to block that person. Several people sending negative reviews will get that person blocked. And you will not appear online when the other person is playing. If you remember his gamertag, you can try calling Live support at 1-800-4My-Xbox and ask them if they can block him for you
How to send a negative player review on Xbox
To submit a negative player review:
1. In the player's profile, select Submit Player Review.
2. Select Avoid This Player.
3. Choose why you want to avoid the player: communication, game behavior, or player skill.
or
Block communications. Open a message from the player and select Block Communications. The player won't be able to send you any messages until you send them one first.
How to unblock someone on Xbox live
Simple send the person you blocked an email through Xbox and they will be unblocked. You can then start playing with your friend.