What is "BLOCK" for on users home page?

People block for different reasons. Some people do it just because they disagree with an opinion, which I don't think is a good reason.

Blocking is a way of preventing a user from answering your questions or contacting you. And also they will be unable to add you as a contact, and even if your profile is public it will be private to them. When you block a user whenever you see their name on the site (even if they change it) there will be a blocked icon next to it to remind you.

When somebody is blocked, while they are logged into Yahoo they will not be able to see your Q&A or network on your profile. And if they happen to see one of your questions and click on it, they will get the message "You cannot view this question at this time"and therefore cannot answer it. They will not be able to email you or add you as a contact either.

However, they will be able to answer any question that you might already have answered on, and if they log out of Yahoo they can view your questions (and even report them), but they still won't be able to answer them.

Possible good reasons to block somebody as I see it:

They answer your questions with really rude or worthless answers, especially anything reportable as a community guidelines violation.

They send you rude or harassing emails.

They have blocked you. Blocking them back helps remind you not to waste time clicking on their question.

You feel their answers are so bad (having seen them on other questions besides your own) you don't want them to answer your questions.

They have been so offensive as an Asker you don't want to answer any more of their questions (again seeing the blocked symbol is a reminder).

They're on your My Fans list and you want them off of it. This is the only way to remove a fan.

It is to block other users who are insulting toward you and stops them visiting your page.

is used to block certain people from contacting you or looking at ur profile.