Consequences of accepting a friend request

What are the consequences of accepting a friend request on battle.net?

Recently I received a friend request from someone and I don't know who it is. I can't think of a way of asking them who they are and why they added me, without accepting the friend request first.

If I accept their friend request, what will change? Will I be able to put things back the way they were before I accepted the friend request?

Solution 1:

Accepting a friend request will allow that player to see when you are online, see what game you are playing (and limited information about what you're doing in that game) and send you battlenet messages. This will also enable certain interactions in some games, such as challenging them in Hearthstone.

You can remove a friend at any time.