A Question about Blockers in HM

I have seen many people block recently in the new mutation map. Especially clan mates blocking for each other. Some think that they don't get banned.
I want to know that :
They do get banned right because its unfair play?
But how many days?
Don't you people think that the person hiding behind the mutant should be banned too?

Thanks for taking your time to read this.
Please share your thoughts!

Edit:

To the people who think they shouldn't get banned.
Firstly lets talk about wall glichers. annoying as a blocker where as your the mutant and you cannot infect them.
Secondly they get banned and we all know that.
Thirdly what is the major difference between a glicher and a blocker that affects the other players in the game.
None.
So blockers should get banned because of there actions that affect the objective of the game and giving them the overall advantage of not getting mutated.
Some people might disagree with that comment but i think its like them using hacks.
Because mainly it gives them a unfair and not a legit advantage.