New section "Keykeeper" - why so many rights?

Question

Habr

On Habré, the “Keykeeper” settings section has just been rolled out, as I understand it, it will be possible to log in to the site using it.

Why do you need so many rights (scopes) when binding via OAuth? For example, for twitter:

Read tweets from your feed.

• Recommend new users.
• Update your profile.
• Post tweets on your behalf.

For contact:

• Access to general information
• Access at any time

For FB and G +, it seems that the rights are basic, not extended like these.

Answer 1

I still do not quite understand why bind at all, and even to several.

Answer 2

Yes, it's not clear.
It also makes sense to integrate with LJ. Quite a few professional people from the Russian IT community blog there.

Answer 3

Well, for contact access at any time so that the authorization of the application does not fly off, as I understand it.

Answer 4

offline scope for VKontakte I think it is needed in order to get a token with an unlimited lifetime