Facebook keeps opening your information to the public. (You need to take some action)
If you do not keep up with all of the latest changes your profile could be looked at by anyone, hence the new Subsribe button.
My advice to you is clean-up your friend list. If you were like me, you used your id to network with strangers and invite them to visit you on your company page. I had a lot of people connected to me that I did not know. Now, I am paring back and connecting with only the people I want to connect with. I am also removing my likes from pages that I liked in the past.
Let me tell you this whole process takes a lot of time and energy, but I think it is in the best interest of everyone. My facebook profile is getting much cleaner by the day and I am actually reading posts again. Before it was just this streaming wall where comments had to be read in a certain amount of time or I would not have any idea of what was happening.